fix(gnovm): handle case of NumStmts = 0 when creating stacktraces

[thehowl]

without the patch, the test fails with this error:

--- FAIL: TestTestdata (1.97s)
    --- FAIL: TestTestdata/issue_outofgas_stacktrace (1.97s)
        testscript.go:558: # test for a bug involving printing stacktraces with missing statements;
            # when dumping out information for a test. (1.763s)
            > loadpkg gno.land/p/demo/avl
            "gno.land/p/demo/avl" package was added to genesis
            > gnoland start
            [stdout]
            node started successfully
            
            > ! gnokey maketx addpkg -pkgdir $WORK -pkgpath gno.land/r/pkg1 -gas-fee 1000000ugnot -gas-wanted 10000000 -broadcast -chainid=tendermint_test test1
            [stdout]
            TX HASH:    sMuFd6oGIxmMHuY1HLbVm6Mi30Nq6cF7mBC5Rt0chug=
            
            [stderr]
            Enter password.
            "gnokey" error: --= Error =--
            Data: runtime error: index out of range [-1]
            Msg Traces:
                0  /home/howl/oc/gno/tm2/pkg/crypto/keys/client/maketx.go:215 - deliver transaction failed: log:msg:0,success:false,log:--= Error =--
            Data: &errors.errorString{s:"runtime error: index out of range [-1]"}
            Msg Traces:
                0  /home/howl/oc/gno/gno.land/pkg/sdk/vm/keeper.go:386 - VM addpkg panic: runtime error: index out of range [-1]
            Machine:
                CheckTypes: false
                Op: [OpHalt OpPopResults]
                Values: (len: 1)
                      #0 (init.2 func()())
                Exprs:
                Stmts:
                Blocks:
                      @(50) Block(ID:0000000000000000000000000000000000000000:0,Addr:0xc00a4c6b40,Source:func init.2() { for i<VPBlock(1,...,Parent:0xc00a17cd20)
             (s vals) @(50) Block(ID:0000000000000000000000000000000000000000:0,Addr:0xc0060b0830,Source:func init.2() { for i<VPBlock(1,...,Parent:0xc0091d9230)
             (s typs) @(50) []
                      @(156) Block(ID:302e5163ca42d53def527ea18dfd0ca4ce3602ba:5,Addr:0xc00a17cd20,Source:file{ package hello; import strc...,Parent:0xc011300780)
                        strconv: (package(strconv strconv) package{})
                        avl: (package(avl gno.land/p/demo/avl) package{})
             (s vals) @(156) Block(ID:0000000000000000000000000000000000000000:0,Addr:0xc0091d9230,Source:file{ package hello; import strc...,Parent:0xc0091d9530)
                        strconv: (package(strconv strconv) package{})
                        avl: (package(avl gno.land/p/demo/avl) package{})
             (s typs) @(156) [package{} package{}]
                Blocks (other):
                      #1 Block(ID:302e5163ca42d53def527ea18dfd0ca4ce3602ba:5,Addr:0xc00a17cd20,Source:file{ package hello; import strc...,Parent:0xc011300780)
                        strconv: (package(strconv strconv) package{})
                        avl: (package(avl gno.land/p/demo/avl) package{})
             (static) #1 Block(ID:0000000000000000000000000000000000000000:0,Addr:0xc0091d9230,Source:file{ package hello; import strc...,Parent:0xc0091d9530)
                        strconv: (package(strconv strconv) package{})
                        avl: (package(avl gno.land/p/demo/avl) package{})
                Frames:
                      #0 [FRAME FUNC:init.2 RECV:(undefined) (0 args) 2/0/0/0/2 LASTPKG:gno.land/r/pkg1 LASTRLM:Realm{Path:"gno.land/r/pkg1",Time:4003}#302E5163CA42D53DEF527EA18DFD0CA4CE3602BA]
                Realm:
                  gno.land/r/pkg1
                Exceptions:
            
            
            Stack Trace:
                0  /home/howl/oc/gno/tm2/pkg/errors/errors.go:20
                1  /home/howl/oc/gno/gno.land/pkg/sdk/vm/keeper.go:386
                2  /home/howl/go/pkg/mod/golang.org/[email protected]/src/runtime/panic.go:770
                3  /home/howl/go/pkg/mod/golang.org/[email protected]/src/runtime/panic.go:114
                4  /home/howl/oc/gno/gnovm/pkg/gnolang/machine.go:482
                5  /home/howl/oc/gno/gnovm/pkg/gnolang/machine.go:793
                6  /home/howl/go/pkg/mod/golang.org/[email protected]/src/runtime/panic.go:770
                7  /home/howl/oc/gno/tm2/pkg/store/types/gas.go:97
                8  /home/howl/oc/gno/tm2/pkg/store/gas/store.go:46
                9  /home/howl/oc/gno/gnovm/pkg/gnolang/store.go:449
               10  /home/howl/oc/gno/gnovm/pkg/gnolang/realm.go:747
               11  /home/howl/oc/gno/gnovm/pkg/gnolang/realm.go:714
               12  /home/howl/oc/gno/gnovm/pkg/gnolang/realm.go:703
               13  /home/howl/oc/gno/gnovm/pkg/gnolang/realm.go:703
               14  /home/howl/oc/gno/gnovm/pkg/gnolang/realm.go:703
               15  /home/howl/oc/gno/gnovm/pkg/gnolang/realm.go:703
               16  /home/howl/oc/gno/gnovm/pkg/gnolang/realm.go:703
               17  /home/howl/oc/gno/gnovm/pkg/gnolang/realm.go:703
               18  /home/howl/oc/gno/gnovm/pkg/gnolang/realm.go:703
               19  /home/howl/oc/gno/gnovm/pkg/gnolang/realm.go:703
               20  /home/howl/oc/gno/gnovm/pkg/gnolang/realm.go:703
               21  /home/howl/oc/gno/gnovm/pkg/gnolang/realm.go:703
               22  /home/howl/oc/gno/gnovm/pkg/gnolang/realm.go:703
               23  /home/howl/oc/gno/gnovm/pkg/gnolang/realm.go:703
               24  /home/howl/oc/gno/gnovm/pkg/gnolang/realm.go:703
               25  /home/howl/oc/gno/gnovm/pkg/gnolang/realm.go:703
               26  /home/howl/oc/gno/gnovm/pkg/gnolang/realm.go:703
               27  /home/howl/oc/gno/gnovm/pkg/gnolang/realm.go:703
               28  /home/howl/oc/gno/gnovm/pkg/gnolang/realm.go:703
               29  /home/howl/oc/gno/gnovm/pkg/gnolang/realm.go:703
               30  /home/howl/oc/gno/gnovm/pkg/gnolang/realm.go:703
               31  /home/howl/oc/gno/gnovm/pkg/gnolang/realm.go:703
            --= /Error =--
            ,events:[]
            --= /Error =--
            
            
            > stderr 'out of gas'
            FAIL: testdata/issue_outofgas_stacktrace.txtar:9: no match for `out of gas` found in stderr
            
FAIL
exit status 1
FAIL	github.com/gnolang/gno/gno.land/cmd/gnoland	2.001s

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 60.89%. Comparing base (09b6241) to head (b5ae57d).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2813      +/-   ##
==========================================
- Coverage   60.90%   60.89%   -0.02%     
==========================================
  Files         564      564              
  Lines       75273    75278       +5     
==========================================
- Hits        45846    45840       -6     
- Misses      26055    26061       +6     
- Partials     3372     3377       +5     

Flag	Coverage Δ
contribs/gnodev	61.46% <ø> (ø)
contribs/gnofaucet	15.31% <ø> (+0.85%)	⬆️
gno.land	67.17% <ø> (ø)
gnovm	65.78% <100.00%> (+<0.01%)	⬆️
misc/genstd	80.54% <ø> (ø)
misc/logos	20.23% <ø> (+0.35%)	⬆️
tm2	61.92% <ø> (-0.12%)	⬇️

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[thehowl]

cc @omarsy, if you can also take a look.

[omarsy]

LGTM, but I'm wondering if is it necessary to include the realm's stack trace if we have an OutOfGasException?

[thehowl]

LGTM, but I'm wondering if is it necessary to include the realm's stack trace if we have an OutOfGasException?

no, and it's not printed, but it was trying to create it anyway. i think the stacktrace is created, but eventually not used.

[thehowl]

ping @deelawn