glsl: Fix input/output structure matching across shader stages
Section 7.4.1 (Shader Interface Matching) of the OpenGL 4.30 spec says:
"Variables or block members declared as structures are considered
to match in type if and only if structure members match in name,
type, qualification, and declaration order."
Fixes: * layout-location-struct.shader_test
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108250 Signed-off-by: Vadym Shovkoplias vadym.shovkoplias@globallogic.com