Add CMake build and fix major Linux blockers.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@121510 91177308-0d34-0410-b5e6-96231b3b80d8

cmake/Modules/MacroEnsureOutOfSourceBuild.cmake

@@ -0,0 +1,18 @@
+# MACRO_ENSURE_OUT_OF_SOURCE_BUILD(<errorMessage>)
+
+macro( MACRO_ENSURE_OUT_OF_SOURCE_BUILD _errorMessage )
+
+string( COMPARE EQUAL "${CMAKE_SOURCE_DIR}" "${CMAKE_BINARY_DIR}" _insource )
+if( _insource )
+ message( SEND_ERROR "${_errorMessage}" )
+ message( FATAL_ERROR
+ "In-source builds are not allowed.
+ CMake would overwrite the makefiles distributed with Compiler-RT.
+ Please create a directory and run cmake from there, passing the path
+ to this source directory as the last argument.
+ This process created the file `CMakeCache.txt' and the directory `CMakeFiles'.
+ Please delete them."
+ )
+endif( _insource )
+
+endmacro( MACRO_ENSURE_OUT_OF_SOURCE_BUILD )