[Mesa-dev] glsl/glcpp: Correctly handle various flavors of newlines

[Carl Worth]

This small series expands the glcpp-test test suite to be able to test all
variations of newlines as allowed by the GLSL specification. It then fixes 4
bugs exposed by that testing until the entire test suite can pass with each of
the 4 allowed newline variations.

The new testing is not yet hooked up to "make check", but must currently be
manually invoked by running ./glcpp-test-cr-lf.