[compiler-rt] Fix target architecture matching

Summary:
Use stricter comparisons for architecture. This prevents cmake from failing
for sysroots which can only compile armhf and not arm, since
arm MATCHES armhf is true, while arm STREQUAL armhf is false.

Reviewers: beanz, compnerd

Subscribers: aemerson, llvm-commits

Differential Revision: https://reviews.llvm.org/D22473

llvm-svn: 276148
diff --git a/compiler-rt/cmake/Modules/CompilerRTUtils.cmake b/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
index 78b6dce..5987cf5 100644
--- a/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
+++ b/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
@@ -126,7 +126,7 @@
   endif()
   if(${CAN_TARGET_${arch}})
     list(APPEND COMPILER_RT_SUPPORTED_ARCH ${arch})
-  elseif("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "${arch}" AND
+  elseif("${COMPILER_RT_DEFAULT_TARGET_ARCH}" STREQUAL "${arch}" AND
          COMPILER_RT_HAS_EXPLICIT_DEFAULT_TARGET_TRIPLE)
     # Bail out if we cannot target the architecture we plan to test.
     message(FATAL_ERROR "Cannot compile for ${arch}:\n${TARGET_${arch}_OUTPUT}")