[Bug preprocessor/63670] Ending C_INCLUDE_PATH with a trailing colon broken

[sch...@linux-m68k.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63670

--- Comment #1 from Andreas Schwab <sch...@linux-m68k.org> ---
Since C_INCLUDE_PATH defines the path for system headers, this doesn't look
like a bug.