Check-sum mismatch warnings for files which aren't found

[vogelsgesang]

LLDB prints warnings about checksum mismatches, also for files which it cannot find.

Example output:

Process 755114 stopped
* thread #93, name = 'task t53', stop reason = Insufficient object size
    frame #0: 0x000055555f0326d0 sqltest`__ubsan_on_report at ubsan_monitor.cpp:40:40
warning: ubsan_monitor.cpp: source file checksum mismatch between line table (d86be2442566cf10902db54006f9794e) and file on disk ()
(lldb) up
frame #1: 0x000055555f02d1c8 sqltest`::~Diag() at ubsan_diag.cpp:360:29
warning: ubsan_diag.cpp: source file checksum mismatch between line table (ea4d3e1240cd730cea597ee52b3505e4) and file on disk ()

In this case, lldb can't find the files ubsan_monitor.cpp and ubsan_diag.cpp on disk.
It still displays a checksum-mismatch which provides no additional value.

Related to #107968

[llvmbot]

@llvm/issue-subscribers-lldb

Author: Adrian Vogelsgesang (vogelsgesang)

LLDB prints warnings about checksum mismatches, also for files which it cannot find.

Example output:

Process 755114 stopped
* thread #<!-- -->93, name = 'task t53', stop reason = Insufficient object size
    frame #<!-- -->0: 0x000055555f0326d0 sqltest`__ubsan_on_report at ubsan_monitor.cpp:40:40
warning: ubsan_monitor.cpp: source file checksum mismatch between line table (d86be2442566cf10902db54006f9794e) and file on disk ()
(lldb) up
frame #<!-- -->1: 0x000055555f02d1c8 sqltest`::~Diag() at ubsan_diag.cpp:360:29
warning: ubsan_diag.cpp: source file checksum mismatch between line table (ea4d3e1240cd730cea597ee52b3505e4) and file on disk ()

In this case, lldb can't find the files ubsan_monitor.cpp and ubsan_diag.cpp on disk.
It still displays a checksum-mismatch which provides no additional value.

Related to #107968

[vogelsgesang]

FYI @JDevlieghere