Toolchain: Make `/path/comp;-argn' behave the same as 'comp;-argn'

When using `cmake ... -DCMAKE_C_COMPILER=gcc;-pipe` first invocation of
CMake worked correctly.

When using `cmake ... -DCMAKE_C_COMPILER=/path/to/gcc;-pipe` first
invocation  of CMake detected a change to CMAKE_C_COMPILER, printed "You
have changed variables" message, and re-ran the initial compiler tests
after configuration was complete and before generation of the project
files.

The difference was due to the cache being forced updated with the new
value of CMAKE_C_COMPILER so that the comparison check passes.
1 file changed