Merge pull request #67286 from RemiBardon/fix-2023-07-13-a

Remove useless `if` statement

Author: swift-ci

unittests/runtime/CMakeLists.txt

@@ -12,9 +12,7 @@ if(("${SWIFT_HOST_VARIANT_SDK}" STREQUAL "${SWIFT_PRIMARY_VARIANT_SDK}") AND
       set(CMAKE_C_COMPILER "${SWIFT_NATIVE_CLANG_TOOLS_PATH}/clang")
     endif()
   elseif(SWIFT_BUILD_RUNTIME_WITH_HOST_COMPILER)
-    if(NOT "${CMAKE_C_COMPILER_ID}" MATCHES "Clang")
-      message(FATAL_ERROR "Building the swift runtime is not supported with ${CMAKE_C_COMPILER_ID}. Use the just-built clang instead.")
-    endif()
+    message(FATAL_ERROR "Building the swift runtime is not supported with ${CMAKE_C_COMPILER_ID}. Use the just-built clang instead.")
   else()
     message(WARNING "Building the swift runtime using the host compiler, and not the just-built clang.")