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.

llvm-svn: 68940

llvm/lib/Bitcode/Writer/BitcodeWriter.cpp

@@ -287,6 +287,7 @@ static unsigned getEncodedLinkage(const GlobalValue *GV) {
   case GlobalValue::PrivateLinkage:      return 9;
   case GlobalValue::WeakODRLinkage:      return 10;
   case GlobalValue::LinkOnceODRLinkage:  return 11;
+  case GlobalValue::AvailableExternallyLinkage:  return 12;
   }
 }