Add a new "available_externally" linkage type. This is intended

to support C99 inline, GNU extern inline, etc.  Related bugzilla's
include PR3517, PR3100, & PR2933.  Nothing uses this yet, but it
appears to work.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68940 91177308-0d34-0410-b5e6-96231b3b80d8

lib/AsmParser/LLLexer.cpp

@@ -487,6 +487,7 @@ lltok::Kind LLLexer::LexIdentifier() {
 
   KEYWORD(private);
   KEYWORD(internal);
+  KEYWORD(available_externally);
   KEYWORD(linkonce);
   KEYWORD(linkonce_odr);
   KEYWORD(weak);

lib/AsmParser/LLParser.cpp

@@ -764,6 +764,9 @@ bool LLParser::ParseOptionalLinkage(unsigned &Res, bool &HasLinkage) {
   case lltok::kw_weak_odr:     Res = GlobalValue::WeakODRLinkage; break;
   case lltok::kw_linkonce:     Res = GlobalValue::LinkOnceAnyLinkage; break;
   case lltok::kw_linkonce_odr: Res = GlobalValue::LinkOnceODRLinkage; break;
+  case lltok::kw_available_externally:
+    Res = GlobalValue::AvailableExternallyLinkage;
+    break;
   case lltok::kw_appending:    Res = GlobalValue::AppendingLinkage; break;
   case lltok::kw_dllexport:    Res = GlobalValue::DLLExportLinkage; break;
   case lltok::kw_common:       Res = GlobalValue::CommonLinkage; break;

lib/AsmParser/LLToken.h

@@ -37,7 +37,7 @@ namespace lltok {
     kw_global,  kw_constant,
 
     kw_private, kw_internal, kw_linkonce, kw_linkonce_odr, kw_weak, kw_weak_odr,
-    kw_appending, kw_dllimport, kw_dllexport, kw_common,
+    kw_appending, kw_dllimport, kw_dllexport, kw_common,kw_available_externally,
     kw_default, kw_hidden, kw_protected,
     kw_extern_weak,
     kw_external, kw_thread_local,