Define a variant of piglit_compile_shader_text() that doesn't call
piglit_report_result() on failure killing the program, which is quite
annoying for tests that expect a compilation to fail and for tests
that are structured in a number of subtests, because a single sub-test
failing to compile a shader will prevent the remaining tests from
running.

I guess this would ideally be the default behavior of
piglit_compile_shader_text(), but with >300 callers in tree it seems
rather difficult to change at this stage.

Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>