[X86] Add 'rdrnd' feature to silvermont to match recent gcc bug fix.

gcc recently fixed this bug https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83546

llvm-svn: 323552
diff --git a/clang/test/Preprocessor/predefined-arch-macros.c b/clang/test/Preprocessor/predefined-arch-macros.c
index bf98107..ef0c022 100644
--- a/clang/test/Preprocessor/predefined-arch-macros.c
+++ b/clang/test/Preprocessor/predefined-arch-macros.c
@@ -1272,6 +1272,7 @@
 // CHECK_SLM_M32: #define __PCLMUL__ 1
 // CHECK_SLM_M32: #define __POPCNT__ 1
 // CHECK_SLM_M32: #define __PRFCHW__ 1
+// CHECK_SLM_M32: #define __RDRND__ 1
 // CHECK_SLM_M32: #define __SSE2__ 1
 // CHECK_SLM_M32: #define __SSE3__ 1
 // CHECK_SLM_M32: #define __SSE4_1__ 1
@@ -1293,6 +1294,7 @@
 // CHECK_SLM_M64: #define __PCLMUL__ 1
 // CHECK_SLM_M64: #define __POPCNT__ 1
 // CHECK_SLM_M64: #define __PRFCHW__ 1
+// CHECK_SLM_M64: #define __RDRND__ 1
 // CHECK_SLM_M64: #define __SSE2_MATH__ 1
 // CHECK_SLM_M64: #define __SSE2__ 1
 // CHECK_SLM_M64: #define __SSE3__ 1