[CMake][runtimes] Set compiler as working even for default target

Even when building builtins and runtimes for the default target
we shouldn't assume that the just built compiler is already useable.
When the compiler uses compiler-rt and libc++ as the default runtime
and C++ library, it won't be usable until we finish building runtimes.

Differential Revision: https://reviews.llvm.org/D39715

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318224 91177308-0d34-0410-b5e6-96231b3b80d8

runtimes/CMakeLists.txt

@@ -216,6 +216,8 @@ else() # if this is included from LLVM's CMake
                                         -DLLVM_RUNTIME_OUTPUT_INTDIR=${LLVM_TOOLS_BINARY_DIR}
                                         -DCMAKE_C_COMPILER_TARGET=${TARGET_TRIPLE}
                                         -DCMAKE_ASM_COMPILER_TARGET=${TARGET_TRIPLE}
+                                        -DCMAKE_C_COMPILER_WORKS=ON
+                                        -DCMAKE_ASM_COMPILER_WORKS=ON
                              PASSTHROUGH_PREFIXES COMPILER_RT
                              USE_TOOLCHAIN
                              ${EXTRA_ARGS})
@@ -244,9 +246,9 @@ else() # if this is included from LLVM's CMake
                                         -DLLVM_RUNTIME_OUTPUT_INTDIR=${LLVM_TOOLS_BINARY_DIR}
                                         -DCMAKE_C_COMPILER_TARGET=${target}
                                         -DCMAKE_ASM_COMPILER_TARGET=${target}
-                                        -DCMAKE_C_COMPILER_WORKS=On
-                                        -DCMAKE_ASM_COMPILER_WORKS=On
-                                        -DCOMPILER_RT_DEFAULT_TARGET_ONLY=On
+                                        -DCMAKE_C_COMPILER_WORKS=ON
+                                        -DCMAKE_ASM_COMPILER_WORKS=ON
+                                        -DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON
                                         ${${target}_extra_args}
                              TOOLCHAIN_TOOLS clang lld llvm-ar llvm-ranlib
                              PASSTHROUGH_PREFIXES COMPILER_RT
@@ -324,6 +326,9 @@ else() # if this is included from LLVM's CMake
                              CMAKE_ARGS -DCOMPILER_RT_BUILD_BUILTINS=Off
                                         -DLLVM_INCLUDE_TESTS=${LLVM_INCLUDE_TESTS}
                                         -DLLVM_LIBRARY_DIR=${LLVM_LIBRARY_DIR}
+                                        -DCMAKE_C_COMPILER_WORKS=ON
+                                        -DCMAKE_CXX_COMPILER_WORKS=ON
+                                        -DCMAKE_ASM_COMPILER_WORKS=ON
                              PASSTHROUGH_PREFIXES ${prefixes}
                              EXTRA_TARGETS ${extra_targets}
                                            ${test_targets}