[llvm][DebugInfo] Add support for _BitInt in DWARFTypePrinter (#168382)

As of recent, LLVM includes the bit-size as a `DW_AT_bit_size` (and as
part of `DW_AT_name`) of `_BitInt`s in DWARF. This allows us to mark
`_BitInt`s as "reconstitutable" when compiling with
`-gsimple-template-names`. However, before doing so we need to make sure
the `DWARFTypePrinter` can reconstruct template parameter values that
have `_BitInt` type. This patch adds support for printing
`DW_TAG_template_value_parameter`s that have `_BitInt` type. Since
`-gsimple-template-names` only omits template parameters that are `<=
64` bit wide, we don't support `_BitInt`s larger than 64 bits.

1 files changed, 6 insertions, 2 deletions

diff --git a/cross-project-tests/debuginfo-tests/clang_llvm_roundtrip/Inputs/simplified_template_names.cpp b/cross-project-tests/debuginfo-tests/clang_llvm_roundtrip/Inputs/simplified_template_names.cpp
index 344005ee9814..6f7ef16d686e 100644
--- a/cross-project-tests/debuginfo-tests/clang_llvm_roundtrip/Inputs/simplified_template_names.cpp
+++ b/cross-project-tests/debuginfo-tests/clang_llvm_roundtrip/Inputs/simplified_template_names.cpp
@@ -95,6 +95,8 @@ struct t12 {
 
 template <decltype(ns::AnonEnum1)> void f10() {}
 
+template <typename T, T V> void f11() {}
+
 int main() {
   struct {
   } A;
@@ -239,8 +241,10 @@ int main() {
   f1<void(t8)>();
   operator_not_really<int>();
   t12 v4;
-  f1<_BitInt(3)>();
-  f1<const unsigned _BitInt(5)>();
+  f11<_BitInt(3), 2>();
+  f11<const unsigned _BitInt(5), 2>();
+  f11<_BitInt(65), 2>();
+  f11<const unsigned _BitInt(65), 2>();
   f1<void(t1<>, t1<>)>();
   f1<int t1<>::*>();
   void fcc() __attribute__((swiftcall));