Hello,

This adds a new global (compiler_info) and procedure 
(test_compiler_info) to GDB's test framework.

For GNUC, the variable is set to:

	gnuc-<major>-<minor>
eg
	gnuc-3-3

while for other compilers it is set to "unknown".  test_compiler_info 
can be used (like test_debug_format) for a specific compiler vis:

	[test_compiler_info gnuc-3-*]

for a version 3 GNU C compiler.

MichaelC? (fernando's on hols)

Andrew