Add support for musl-libc on ARM Linux.

Patch by Lei Zhang!

llvm-svn: 273726
diff --git a/llvm/lib/Target/ARM/ARMAsmPrinter.cpp b/llvm/lib/Target/ARM/ARMAsmPrinter.cpp
index 25d2ec9..72b4c6a 100644
--- a/llvm/lib/Target/ARM/ARMAsmPrinter.cpp
+++ b/llvm/lib/Target/ARM/ARMAsmPrinter.cpp
@@ -562,7 +562,8 @@
   ARMTargetStreamer &ATS = static_cast<ARMTargetStreamer &>(TS);
 
   if (OptimizationGoals > 0 &&
-      (Subtarget->isTargetAEABI() || Subtarget->isTargetGNUAEABI()))
+      (Subtarget->isTargetAEABI() || Subtarget->isTargetGNUAEABI() ||
+       Subtarget->isTargetMuslAEABI()))
     ATS.emitAttribute(ARMBuildAttrs::ABI_optimization_goals, OptimizationGoals);
   OptimizationGoals = -1;