[clang-cl] support /Oy- on aarch64

MSVC supports /Oy- on aarch64, so clang-cl should too.

Patch by Nathan Froyd!

Differential Revision: https://reviews.llvm.org/D57838

llvm-svn: 353402
diff --git a/clang/test/Driver/cl-options.c b/clang/test/Driver/cl-options.c
index 4087ef3..1fa2ae3 100644
--- a/clang/test/Driver/cl-options.c
+++ b/clang/test/Driver/cl-options.c
@@ -178,6 +178,10 @@
 // Oy_2: -momit-leaf-frame-pointer
 // Oy_2: -O2
 
+// RUN: %clang_cl --target=aarch64-pc-windows-msvc -Werror /Oy- /O2 -### -- %s 2>&1 | FileCheck -check-prefix=Oy_aarch64 %s
+// Oy_aarch64: -mdisable-fp-elim
+// Oy_aarch64: -O2
+
 // RUN: %clang_cl --target=i686-pc-win32 -Werror /O2 /O2 -### -- %s 2>&1 | FileCheck -check-prefix=O2O2 %s
 // O2O2: "-O2"