Tests: Enable Assembler test case when CMAKE_OSX_ARCHITECTURES has one value

Tests/Assembler/CMakeLists.txt

@@ -8,7 +8,7 @@ set(SRCS)
 # (at least) the following toolchains can process assembler files directly
 # and also generate assembler files from C:
 if("${CMAKE_GENERATOR}" MATCHES "Makefile|Xcode|Ninja" AND
-    NOT CMAKE_OSX_ARCHITECTURES)
+    NOT CMAKE_OSX_ARCHITECTURES MATCHES ";")
   if((CMAKE_C_COMPILER_ID MATCHES "^(GNU|Clang|AppleClang|HP|SunPro|XL)$") OR (CMAKE_C_COMPILER_ID STREQUAL "Intel"  AND  UNIX)
      AND NOT (CMAKE_C_COMPILER_ID STREQUAL "Clang" AND "x${CMAKE_C_COMPILER_FRONTEND_VARIANT}" STREQUAL "xMSVC"))
     set(C_FLAGS "${CMAKE_C_FLAGS}")
@@ -16,6 +16,9 @@ if("${CMAKE_GENERATOR}" MATCHES "Makefile|Xcode|Ninja" AND
     if(CMAKE_OSX_SYSROOT AND CMAKE_C_SYSROOT_FLAG AND NOT ";${C_FLAGS};" MATCHES ";${CMAKE_C_SYSROOT_FLAG};")
       list(APPEND C_FLAGS ${CMAKE_C_SYSROOT_FLAG} ${CMAKE_OSX_SYSROOT})
     endif()
+    if(CMAKE_OSX_ARCHITECTURES)
+      list(APPEND C_FLAGS -arch ${CMAKE_OSX_ARCHITECTURES})
+    endif()
     # Clang on OS X, and perhaps other compilers, do not support -g
     # for both generating and assembling, so drop it from generating.
     list(REMOVE_ITEM C_FLAGS -g)