Add weak reference directive.

llvm-svn: 32091
diff --git a/llvm/lib/Target/PowerPC/PPCTargetAsmInfo.cpp b/llvm/lib/Target/PowerPC/PPCTargetAsmInfo.cpp
index f8848f5..1e38009 100644
--- a/llvm/lib/Target/PowerPC/PPCTargetAsmInfo.cpp
+++ b/llvm/lib/Target/PowerPC/PPCTargetAsmInfo.cpp
@@ -33,6 +33,7 @@
   StaticCtorsSection = ".mod_init_func";
   StaticDtorsSection = ".mod_term_func";
   UsedDirective = "\t.no_dead_strip\t";
+  WeakRefDirective = "\t.weak_reference\t";
   InlineAsmStart = "# InlineAsm Start";
   InlineAsmEnd = "# InlineAsm End";