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, 5 insertions, 5 deletions

diff --git a/llvm/test/DebugInfo/ARM/tls.ll b/llvm/test/DebugInfo/ARM/tls.ll
index e54d1600476..c4be0303172 100644
--- a/llvm/test/DebugInfo/ARM/tls.ll
+++ b/llvm/test/DebugInfo/ARM/tls.ll
@@ -16,13 +16,13 @@
 ; The debug relocation of the address of the tls variable
 ; CHECK: .long x(tlsldo)
 
-!0 = metadata !{i32 786449, metadata !1, i32 12, metadata !"clang version 3.5 ", i1 false, metadata !"", i32 0, metadata !2, metadata !2, metadata !2, metadata !3, metadata !2, metadata !""} ; [ DW_TAG_compile_unit ] [/tmp/tls.c] [DW_LANG_C99]
+!0 = metadata !{metadata !"0x11\0012\00clang version 3.5 \000\00\000\00\000", metadata !1, metadata !2, metadata !2, metadata !2, metadata !3, metadata !2} ; [ DW_TAG_compile_unit ] [/tmp/tls.c] [DW_LANG_C99]
 !1 = metadata !{metadata !"tls.c", metadata !"/tmp"}
 !2 = metadata !{}
 !3 = metadata !{metadata !4}
-!4 = metadata !{i32 786484, i32 0, null, metadata !"x", metadata !"x", metadata !"", metadata !5, i32 1, metadata !6, i32 0, i32 1, i32* @x, null} ; [ DW_TAG_variable ] [x] [line 1] [def]
-!5 = metadata !{i32 786473, metadata !1}          ; [ DW_TAG_file_type ] [/tmp/tls.c]
-!6 = metadata !{i32 786468, null, null, metadata !"int", i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
+!4 = metadata !{metadata !"0x34\00x\00x\00\001\000\001", null, metadata !5, metadata !6, i32* @x, null} ; [ DW_TAG_variable ] [x] [line 1] [def]
+!5 = metadata !{metadata !"0x29", metadata !1}          ; [ DW_TAG_file_type ] [/tmp/tls.c]
+!6 = metadata !{metadata !"0x24\00int\000\0032\0032\000\000\005", null, null} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
 !7 = metadata !{i32 2, metadata !"Dwarf Version", i32 4}
-!8 = metadata !{i32 1, metadata !"Debug Info Version", i32 1}
+!8 = metadata !{i32 1, metadata !"Debug Info Version", i32 2}
 !9 = metadata !{metadata !"clang version 3.5 "}