glcpp: Implement token pasting for non-function-like macros

glcpp: Implement token pasting for non-function-like macros

This is as simple as abstracting one existing block of code into a
function call and then adding a single call to that function for the
case of a non-function-like macro.

This fixes the recently-added 097-paste-with-non-function-macro test
as well as the following piglit tests:

	spec/glsl-1.30/preprocessor/concat/concat-01.frag
	spec/glsl-1.30/preprocessor/concat/concat-02.frag

Also, the concat-04.frag test now passes for the right reason. The
test is intended to fail the compilation, but before this commit it
was failing compilation (and hence passing the test) for the wrong
reason.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Carl Worth <cworth@cworth.org>