[cfe-dev] Stop searching gcc dirs for C compiler headers

[Chris Lattner]

Heads up,

I just committed this patch:
http://lists.cs.uiuc.edu/pipermail/cfe-commits/Week-of-Mon-20090216/012615.html

This changes clang to stop searching for the GCC versions of "float.h"  
and friends.  In theory, all of these headers are implemented and I  
think that clang should find them ('make test' passes at least).   
However, there is always some possibility of breakage.  If you see  
any, please let me know.  Also, as a workaround, you can define system  
header search paths with the CPATH or C_INCLUDE_PATH environment  
variables.

The motivation for doing this is that the GCC GPL2 header files have a  
license clause which states "this file is GPL unless you compile it  
with GCC".  Since Clang is not GCC, this implicitly makes all programs  
compiled with Clang GPL that use these.  This is "bad", and our  
versions of the headers are now feature complete, so it is time to  
sever this tie.

Please let me know if you notice any problems.  With luck, you won't  
notice any change! :)

-Chris