allow partially materialized modules to be written out, which just strips out
the functions which haven't been read.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36999 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index 1ea7633..eddae26 100644
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -256,6 +256,7 @@
 static unsigned getEncodedLinkage(const GlobalValue *GV) {
   switch (GV->getLinkage()) {
   default: assert(0 && "Invalid linkage!");
+  case GlobalValue::GhostLinkage:  // Map ghost linkage onto external.
   case GlobalValue::ExternalLinkage:     return 0;
   case GlobalValue::WeakLinkage:         return 1;
   case GlobalValue::AppendingLinkage:    return 2;