Add includer to gtest for include file tests.

Turn on debug info flag for non-semantic debug test.

Test/spv.debuginfo.include.glsl.frag

@@ -0,0 +1,12 @@
+#version 450
+
+#extension GL_GOOGLE_include_directive : require
+#include "spv.debuginfo.include.glsl.h"
+
+vec4 mainFileFunction(vec4 v) {
+	return -v;
+}
+
+void main() {
+	headerOut = headerFunction(mainFileFunction(headerUboItem));
+}