libcpp: Merge fixes from upstream Fixes: GCC preprocessor/29966: GCC preprocessor/28709: GCC c/31924 GCC preprocessor/14331 gcc: add Apple-compatible -Wnewline-eof Obtained from: gcc per-4.3 (rev. 121340, 124356, 124358, 124730, 125212, 125255 ; GPLv2) Apple Inc. (Apple GCC 4.2 - 5531)