[sanitizer] Passthrough CMAKE_OSX_DEPLOYMENT_TARGET when building compiler-rt from clang/runtime/CMakeLists.txt

This breaks some Swift builds, because Swift's build scripts explicitly set CMAKE_OSX_DEPLOYMENT_TARGET. This however isn't propagated to the compiler-rt build, causing build errors.

Differential Revision: https://reviews.llvm.org/D26558

llvm-svn: 286898

Author: kubamracek

clang/runtime/CMakeLists.txt

@@ -77,6 +77,7 @@ if(LLVM_BUILD_EXTERNAL_COMPILER_RT AND EXISTS ${COMPILER_RT_SRC_ROOT}/)
                -DCOMPILER_RT_INCLUDE_TESTS=${LLVM_INCLUDE_TESTS}
                -DCMAKE_INSTALL_PREFIX=${CMAKE_INSTALL_PREFIX}
                -DLLVM_LIBDIR_SUFFIX=${LLVM_LIBDIR_SUFFIX}
+               -DCMAKE_OSX_DEPLOYMENT_TARGET=${CMAKE_OSX_DEPLOYMENT_TARGET}
                ${COMPILER_RT_PASSTHROUGH_VARIABLES}
     INSTALL_COMMAND ""
     STEP_TARGETS configure build