Revert "Revert "DI: Fold constant arguments into a single MDString""

This reverts commit r218918, effectively reapplying r218914 after fixing
an Ocaml bindings test and an Asan crash.  The root cause of the latter
was a tightened-up check in `DILexicalBlock::Verify()`, so I'll file a
PR to investigate who requires the loose check (and why).

Original commit message follows.

--

This patch addresses the first stage of PR17891 by folding constant
arguments together into a single MDString.  Integers are stringified and
a `\0` character is used as a separator.

Part of PR17891.

Note: I've attached my testcases upgrade scripts to the PR.  If I've
just broken your out-of-tree testcases, they might help.

llvm-svn: 219010

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/test/DebugInfo/COFF/asan-module-without-functions.ll b/llvm/test/DebugInfo/COFF/asan-module-without-functions.ll
index 419faa0e0f3..d5af109479b 100644
--- a/llvm/test/DebugInfo/COFF/asan-module-without-functions.ll
+++ b/llvm/test/DebugInfo/COFF/asan-module-without-functions.ll
@@ -45,9 +45,9 @@ define internal void @asan.module_dtor() {
 !llvm.module.flags = !{!3, !4}
 !llvm.ident = !{!5}
 
-!0 = metadata !{i32 786449, metadata !1, i32 12, metadata !"clang version 3.5.0 ", i1 false, metadata !"", i32 0, metadata !2, metadata !2, metadata !2, metadata !2, metadata !2, metadata !"", i32 2} ; [ DW_TAG_compile_unit ] [D:\/asan.c] [DW_LANG_C99]
+!0 = metadata !{metadata !"0x11\0012\00clang version 3.5.0 \000\00\000\00\002", metadata !1, metadata !2, metadata !2, metadata !2, metadata !2, metadata !2} ; [ DW_TAG_compile_unit ] [D:\/asan.c] [DW_LANG_C99]
 !1 = metadata !{metadata !"asan.c", metadata !"D:\5C"}
 !2 = metadata !{}
 !3 = metadata !{i32 2, metadata !"Dwarf Version", i32 4}
-!4 = metadata !{i32 1, metadata !"Debug Info Version", i32 1}
+!4 = metadata !{i32 1, metadata !"Debug Info Version", i32 2}
 !5 = metadata !{metadata !"clang version 3.5.0 "}