Rollup merge of #47618 - mrhota:dw_at_noreturn, r=michaelwoerister

Teach rustc about DW_AT_noreturn and a few more DIFlags

We achieve two small things with this PR:
1. We provide definitions for a few additional llvm debuginfo flags
1. We _use_ one of these new flags, `FlagNoReturn`, and add it to debuginfo for functions with the never return type (`!`).

1 files changed, 18 insertions, 2 deletions

diff --git a/src/rustllvm/RustWrapper.cpp b/src/rustllvm/RustWrapper.cpp
index 0fe533d447b..82aafb7c355 100644
--- a/src/rustllvm/RustWrapper.cpp
+++ b/src/rustllvm/RustWrapper.cpp
@@ -457,9 +457,13 @@ enum class LLVMRustDIFlags : uint32_t {
   FlagStaticMember = (1 << 12),
   FlagLValueReference = (1 << 13),
   FlagRValueReference = (1 << 14),
-  FlagMainSubprogram      = (1 << 21),
+  FlagExternalTypeRef = (1 << 15),
+  FlagIntroducedVirtual = (1 << 18),
+  FlagBitField = (1 << 19),
+  FlagNoReturn = (1 << 20),
+  FlagMainSubprogram = (1 << 21),
   // Do not add values that are not supported by the minimum LLVM
-  // version we support!
+  // version we support! see llvm/include/llvm/IR/DebugInfoFlags.def
 };
 
 inline LLVMRustDIFlags operator&(LLVMRustDIFlags A, LLVMRustDIFlags B) {
@@ -544,7 +548,19 @@ static unsigned fromRust(LLVMRustDIFlags Flags) {
   if (isSet(Flags & LLVMRustDIFlags::FlagRValueReference)) {
     Result |= DINode::DIFlags::FlagRValueReference;
   }
+  if (isSet(Flags & LLVMRustDIFlags::FlagExternalTypeRef)) {
+    Result |= DINode::DIFlags::FlagExternalTypeRef;
+  }
+  if (isSet(Flags & LLVMRustDIFlags::FlagIntroducedVirtual)) {
+    Result |= DINode::DIFlags::FlagIntroducedVirtual;
+  }
+  if (isSet(Flags & LLVMRustDIFlags::FlagBitField)) {
+    Result |= DINode::DIFlags::FlagBitField;
+  }
 #if LLVM_RUSTLLVM || LLVM_VERSION_GE(4, 0)
+  if (isSet(Flags & LLVMRustDIFlags::FlagNoReturn)) {
+    Result |= DINode::DIFlags::FlagNoReturn;
+  }
   if (isSet(Flags & LLVMRustDIFlags::FlagMainSubprogram)) {
     Result |= DINode::DIFlags::FlagMainSubprogram;
   }