[DeclCXX] Remove unknown external linkage specifications

Partial revert of r372681 "Support for DWARF-5 C++ language tags".

The change introduced new external linkage languages ("C++11" and
"C++14") which not supported in C++.

It also changed the definition of the existing enum to use the DWARF
constants. The problem is that "LinkageSpecDeclBits.Language" (the field
that reserves this enum) is actually defined as 3 bits length
(bitfield), which cannot contain the new DWARF constants. Defining the
enum as integer literals is more appropriate for maintaining valid
values.

Differential Revision: https://reviews.llvm.org/D69935

1 files changed, 1 insertions, 3 deletions

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 768361d548d..0e561693f20 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -5192,9 +5192,7 @@ void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) {
 // EmitLinkageSpec - Emit all declarations in a linkage spec.
 void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) {
   if (LSD->getLanguage() != LinkageSpecDecl::lang_c &&
-      LSD->getLanguage() != LinkageSpecDecl::lang_cxx &&
-      LSD->getLanguage() != LinkageSpecDecl::lang_cxx_11 &&
-      LSD->getLanguage() != LinkageSpecDecl::lang_cxx_14) {
+      LSD->getLanguage() != LinkageSpecDecl::lang_cxx) {
     ErrorUnsupported(LSD, "linkage spec");
     return;
   }