PNaCl: Check we don't crash in -replace-ptrs-with-ints with odd metadata operands.

When LLVM proper is merge with `pnacl-llvm`, ensure the recent metadata changes don't cause a regression in `pnacl-llvm`.

BUG=
[email protected], [email protected]

Review URL: https://codereview.chromium.org/1085483003

Author: jfbastien

test/Transforms/NaCl/replace-ptrs-with-ints.ll

@@ -416,11 +416,19 @@ define void @debug_declare(i32 %val) {
 define void @debug_value(i32 %val, i8* %ptr) {
   tail call void @llvm.dbg.value(metadata !{i32 %val}, i64 1, metadata !1, metadata !14)
   tail call void @llvm.dbg.value(metadata !{i8* %ptr}, i64 2, metadata !1, metadata !14)
+
+; check that we don't crash when encountering odd things:
+  tail call void @llvm.dbg.value(metadata !{i8* null}, i64 3, metadata !1, metadata !14)
+  tail call void @llvm.dbg.value(metadata !{i8* undef}, i64 4, metadata !1, metadata !14)
+  tail call void @llvm.dbg.value(metadata !{}, i64 5, metadata !1, metadata !14)
   ret void
 }
 ; CHECK: define void @debug_value(i32 %val, i32 %ptr) {
 ; CHECK-NEXT: call void @llvm.dbg.value(metadata !{null}, i64 1, metadata !1, metadata !14)
 ; CHECK-NEXT: call void @llvm.dbg.value(metadata !{null}, i64 2, metadata !1, metadata !14)
+; CHECK-NEXT: call void @llvm.dbg.value(metadata !15, i64 3, metadata !1, metadata !14)
+; CHECK-NEXT: call void @llvm.dbg.value(metadata !16, i64 4, metadata !1, metadata !14)
+; CHECK-NEXT: call void @llvm.dbg.value(metadata !2, i64 5, metadata !1, metadata !14)
 ; CHECK-NEXT: ret void