sets bit 0 of the function address of thumb function in .symtab
("T is 1 if the target symbol S has type STT_FUNC and the
symbol addresses a Thumb instruction ;it is 0 otherwise."
from "ELF for the ARM Architecture" 4.7.1.2)

Patch by Koan-Sin Tan!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131406 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCAsmStreamer.cpp b/lib/MC/MCAsmStreamer.cpp
index 603ae83..ee68a37 100644
--- a/lib/MC/MCAsmStreamer.cpp
+++ b/lib/MC/MCAsmStreamer.cpp
@@ -323,7 +323,8 @@
   // This needs to emit to a temporary string to get properly quoted
   // MCSymbols when they have spaces in them.
   OS << "\t.thumb_func";
-  if (Func)
+  // Only Mach-O hasSubsectionsViaSymbols()
+  if (MAI.hasSubsectionsViaSymbols())
     OS << '\t' << *Func;
   EmitEOL();
 }