[AIX]Emit function descriptor csect in assembly

This patch emits the function descriptor csect for functions with definitions
under both 32-bit/64-bit mode on AIX.

Differential Revision: https://reviews.llvm.org/D66724

llvm-svn: 373009
diff --git a/llvm/lib/MC/MCMachOStreamer.cpp b/llvm/lib/MC/MCMachOStreamer.cpp
index 613f255..8e558a3 100644
--- a/llvm/lib/MC/MCMachOStreamer.cpp
+++ b/llvm/lib/MC/MCMachOStreamer.cpp
@@ -330,6 +330,7 @@
   case MCSA_Protected:
   case MCSA_Weak:
   case MCSA_Local:
+  case MCSA_LGlobal:
     return false;
 
   case MCSA_Global: