Reapply "[DebugInfo] Make DIArgList inherit from Metadata and always unique"

This reverts commit 0fd5dc94380d5fe666dc6c603b4bb782cef743e7.

The original commit removed DIArgLists from being in an MDNode map, but did
not insert a new `delete` in the LLVMContextImpl destructor. This
reapply adds that call to delete, preventing a memory leak.

1 files changed, 7 insertions, 5 deletions

diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index d16b5c7..9c21cc6 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -336,8 +336,7 @@ private:
                     unsigned Abbrev);
   void writeDIMacroFile(const DIMacroFile *N, SmallVectorImpl<uint64_t> &Record,
                         unsigned Abbrev);
-  void writeDIArgList(const DIArgList *N, SmallVectorImpl<uint64_t> &Record,
-                      unsigned Abbrev);
+  void writeDIArgList(const DIArgList *N, SmallVectorImpl<uint64_t> &Record);
   void writeDIModule(const DIModule *N, SmallVectorImpl<uint64_t> &Record,
                      unsigned Abbrev);
   void writeDIAssignID(const DIAssignID *N, SmallVectorImpl<uint64_t> &Record,
@@ -1975,13 +1974,12 @@ void ModuleBitcodeWriter::writeDIMacroFile(const DIMacroFile *N,
 }
 
 void ModuleBitcodeWriter::writeDIArgList(const DIArgList *N,
-                                         SmallVectorImpl<uint64_t> &Record,
-                                         unsigned Abbrev) {
+                                         SmallVectorImpl<uint64_t> &Record) {
   Record.reserve(N->getArgs().size());
   for (ValueAsMetadata *MD : N->getArgs())
     Record.push_back(VE.getMetadataID(MD));
 
-  Stream.EmitRecord(bitc::METADATA_ARG_LIST, Record, Abbrev);
+  Stream.EmitRecord(bitc::METADATA_ARG_LIST, Record);
   Record.clear();
 }
 
@@ -2264,6 +2262,10 @@ void ModuleBitcodeWriter::writeMetadataRecords(
 #include "llvm/IR/Metadata.def"
       }
     }
+    if (auto *AL = dyn_cast<DIArgList>(MD)) {
+      writeDIArgList(AL, Record);
+      continue;
+    }
     writeValueAsMetadata(cast<ValueAsMetadata>(MD), Record);
   }
 }