[RemoveDIs][ValueMapper] Remap DIAssignIDs in DPValues (#81595)

Fix crash raised in comments for 5c9f768

Author: OCHyams

llvm/lib/Transforms/Utils/ValueMapper.cpp

@@ -552,6 +552,7 @@ void Mapper::remapDPValue(DPValue &V) {
       V.setKillAddress();
     else if (NewAddr)
       V.setAddress(NewAddr);
+    V.setAssignId(cast<DIAssignID>(mapMetadata(V.getAssignID())));
   }
 
   // Find Value operands and remap those.

llvm/test/DebugInfo/Generic/ipsccp-remap-assign-id.ll

@@ -0,0 +1,59 @@
+; RUN: opt -passes=ipsccp %s -S -o - | FileCheck %s
+; RUN: opt --try-experimental-debuginfo-iterators -passes=ipsccp %s -S -o - | FileCheck %s
+
+;; Check the dbg.assign DIAssignID operand gets remapped after cloning.
+
+; CHECK: %tmp = alloca [4096 x i32], i32 0, align 16, !DIAssignID ![[ID1:[0-9]+]]
+; CHECK-NEXT: dbg.assign(metadata i1 undef, metadata !{{.*}}, metadata !DIExpression(), metadata ![[ID1]], metadata ptr %tmp, metadata !DIExpression())
+;
+; CHECK: %tmp = alloca [4096 x i32], i32 0, align 16, !DIAssignID ![[ID2:[0-9]+]]
+; CHECK-NEXT: dbg.assign(metadata i1 undef, metadata !{{.*}}, metadata !DIExpression(), metadata ![[ID2]], metadata ptr %tmp, metadata !DIExpression())
+
+; Function Attrs: mustprogress nocallback nofree nosync nounwind speculatable willreturn memory(none)
+declare void @llvm.dbg.declare(metadata, metadata, metadata)
+
+define void @inv_txfm_add_dct_dct_4x4_c() {
+entry:
+  call void @inv_txfm_add_c(ptr @dav1d_inv_dct4_1d_c)
+  ret void
+}
+
+declare void @llvm.memset.p0.i64(ptr nocapture writeonly, i8, i64, i1 immarg)
+
+; Function Attrs: noinline
+define void @inv_txfm_add_c(ptr %first_1d_fn) #2 {
+entry:
+  %tmp = alloca [4096 x i32], i32 0, align 16, !DIAssignID !5
+  tail call void @llvm.dbg.assign(metadata i1 undef, metadata !6, metadata !DIExpression(), metadata !5, metadata ptr %tmp, metadata !DIExpression()), !dbg !16
+  call void @llvm.memset.p0.i64(ptr %tmp, i8 0, i64 0, i1 false), !DIAssignID !17
+  call void %first_1d_fn(ptr null, i64 0, i32 0, i32 0)
+  ret void
+}
+
+declare void @dav1d_inv_dct4_1d_c(ptr, i64, i32, i32)
+
+declare void @llvm.dbg.assign(metadata, metadata, metadata, metadata, metadata, metadata)
+
+attributes #2 = { noinline }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C11, file: !1, isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !2, splitDebugInlining: false, nameTableKind: GNU)
+!1 = !DIFile(filename: "itx_tmpl.c", directory: ".")
+!2 = !{}
+!3 = !{i32 2, !"Debug Info Version", i32 3}
+!4 = !{i32 7, !"debug-info-assignment-tracking", i1 true}
+!5 = distinct !DIAssignID()
+!6 = !DILocalVariable(name: "tmp", scope: !7, file: !1, line: 78, type: !10)
+!7 = distinct !DISubprogram(name: "inv_txfm_add_c", scope: !1, file: !1, line: 41, type: !8, scopeLine: 45, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !2)
+!8 = distinct !DISubroutineType(types: !9)
+!9 = !{null}
+!10 = !DICompositeType(tag: DW_TAG_array_type, baseType: !11, size: 131072, elements: !2)
+!11 = !DIDerivedType(tag: DW_TAG_typedef, name: "int32_t", file: !12, line: 26, baseType: !13)
+!12 = !DIFile(filename: "stdint-intn.h", directory: ".")
+!13 = !DIDerivedType(tag: DW_TAG_typedef, name: "__int32_t", file: !14, line: 41, baseType: !15)
+!14 = !DIFile(filename: "types.h", directory: ".")
+!15 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!16 = !DILocation(line: 0, scope: !7)
+!17 = distinct !DIAssignID()