[debuginfo-tests] Un-XFAIL now passing unused-merged-value.c test

[Michael137]

Summary

This test would previously expect one of the parameters to have
an incorrect DW_AT_location. Stepping through fun with a debugger
would then not reflect updates to one of the parameters.

With a recent change to Clang's DeadArgumentEliminationPass
(see 879f5118fc74657e4a5c4eff6810098e1eed75ac) the generated
DWARF does not contain a location for parama, and stepping through
the function with lldb works as expected.

[Michael137]

@Orlando FYI, this test now XPASSes as of 879f5118fc74657e4a5c4eff6810098e1eed75ac (https://reviews.llvm.org/D128830)

Do you want to flip the XFAIL or find another way of reproducing the behaviour?

[Orlando]

Hi @Michael137. Removing the XFAIL is ok in this case - "optimized out" is preferable to seeing incorrect values and having the test pass now that this is the case is intended. Thanks for checking and updating this!

cross-project-tests/debuginfo-tests/dexter-tests/memvars/unused-merged-value.c

1–4

nit: missing full stop?

[Michael137]

• Fix typo

cross-project-tests/debuginfo-tests/dexter-tests/memvars/unused-merged-value.c

-// XFAIL: *
-// Incorrect location for variable "parama", see PR48719.
+// Location for variable "parama" optimized out.
+// Previously it would carry incorrect location
+// information in debug-info, see PR48719.
+// Now, the location is simply not emitted.
 
 // REQUIRES: lldb
 // UNSUPPORTED: system-windows
 // RUN: %dexter --fail-lt 0.1 -w --debugger lldb \
 // RUN:     --builder 'clang-c'  --cflags "-O3 -glldb" -- %s
 // See NOTE at end for more info about the RUN command.
 
 // 1. SROA/mem2reg fully promotes parama.