[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, 0 insertions, 2 deletions

diff --git a/clang/lib/Sema/SemaModule.cpp b/clang/lib/Sema/SemaModule.cpp
index 1fca351bfb0..10de0ca9122 100644
--- a/clang/lib/Sema/SemaModule.cpp
+++ b/clang/lib/Sema/SemaModule.cpp
@@ -31,8 +31,6 @@ static void checkModuleImportContext(Sema &S, Module *M,
         ExternCLoc = LSD->getBeginLoc();
       break;
     case LinkageSpecDecl::lang_cxx:
-    case LinkageSpecDecl::lang_cxx_11:
-    case LinkageSpecDecl::lang_cxx_14:
       break;
     }
     DC = LSD->getParent();