[CMake] Workaround for PR24144: avoid installing libcxx_tsan and libcxx_msan by default "ninja install" command.

Summary:
Exclude external libc++ builds from "all" target, so that they are only
build on demand, and are not installed together with LLVM/Clang.

Reviewers: hans

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D11252

llvm-svn: 242424

compiler-rt/cmake/Modules/AddCompilerRT.cmake

@@ -245,6 +245,7 @@ macro(add_custom_libcxx name prefix)
     list(APPEND LIBCXX_DEPS clang)
   endif()
 
+  set(EXCLUDE_FROM_ALL TRUE)
   ExternalProject_Add(${name}
     PREFIX ${prefix}
     SOURCE_DIR ${COMPILER_RT_LIBCXX_PATH}
@@ -271,4 +272,5 @@ macro(add_custom_libcxx name prefix)
     DEPENDERS configure
     DEPENDS ${LIBCXX_DEPS}
     )
+  set(EXCLUDE_FROM_ALL FALSE)
 endmacro()