fbde6a8636
* Support for custom build toolchains ISSUE #297 Locate the header file path of DORIS_GCC_HOME, add them to the CPLUS_INCLUDE_PATH environment variable. So clang can find it. * Compatible with custom toolchain for clang ISSUE #297 1. Find default header file paths of DORIS_GCC_HOME and set as enviroment variable CLANG_COMPATIBLE_FLAGS. 2. Explicitly add these paths to CLANG_INCLUDE_FLAGS.