glsl: add warning-test

It executes compiler-glsl on all the available shaders, and it checks
that the outcome is the expected.

Bash code based on the already existing optimization-test

v2: rebasing: use --version option

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
diff --git a/src/compiler/Makefile.glsl.am b/src/compiler/Makefile.glsl.am
index 23c2a6b..4e90f16 100644
--- a/src/compiler/Makefile.glsl.am
+++ b/src/compiler/Makefile.glsl.am
@@ -35,7 +35,8 @@
 	glsl/tests/general-ir-test			\
 	glsl/tests/optimization-test			\
 	glsl/tests/sampler-types-test			\
-	glsl/tests/uniform-initializer-test
+	glsl/tests/uniform-initializer-test             \
+	glsl/tests/warnings-test
 
 TESTS_ENVIRONMENT= \
 	export PYTHON2=$(PYTHON2); \