[PATCH] Allow embedded timestamps by C/C++ macros to be set externally

[Joseph Myers]

Since cpplib is a library and doesn't have any existing getenv calls, I 
wonder if it would be better for the cpplib client (i.e. something in the 
gcc/ directory) to be what calls getenv and then informs cpplib of the 
timestamp it should treat as being the time of compilation.

-- 
Joseph S. Myers
joseph@codesourcery.com