[DWARF] Add support for DW_TAG_template_alias for template aliases (#88943)

Part 1 of fix for issue
https://github.com/llvm/llvm-project/issues/54624

Split from PR #87623. Clang front end changes to follow.

Use DICompositeType to represent the template alias, using its extraData
field as a tuple of DITemplateParameter to describe the template
parameters.

Added template-alias.ll  - Check DWARF emission.
Modified  frame-types.s  - Check llvm-symbolizer understands the DIE.

1 files changed, 11 insertions, 0 deletions

diff --git a/llvm/lib/IR/DIBuilder.cpp b/llvm/lib/IR/DIBuilder.cpp
index f86e557..f39149a 100644
--- a/llvm/lib/IR/DIBuilder.cpp
+++ b/llvm/lib/IR/DIBuilder.cpp
@@ -356,6 +356,17 @@ DIDerivedType *DIBuilder::createTypedef(DIType *Ty, StringRef Name,
                             nullptr, Annotations);
 }
 
+DIDerivedType *
+DIBuilder::createTemplateAlias(DIType *Ty, StringRef Name, DIFile *File,
+                               unsigned LineNo, DIScope *Context,
+                               DINodeArray TParams, uint32_t AlignInBits,
+                               DINode::DIFlags Flags, DINodeArray Annotations) {
+  return DIDerivedType::get(VMContext, dwarf::DW_TAG_template_alias, Name, File,
+                            LineNo, getNonCompileUnitScope(Context), Ty, 0,
+                            AlignInBits, 0, std::nullopt, std::nullopt, Flags,
+                            TParams.get(), Annotations);
+}
+
 DIDerivedType *DIBuilder::createFriend(DIType *Ty, DIType *FriendTy) {
   assert(Ty && "Invalid type!");
   assert(FriendTy && "Invalid friend type!");