glsl2: Eliminate tokens for square matrix short names

MAT2 and MAT2X2, for example, are treated identically by the parser.
The language version based error checking (becuase mat2x2 is not
available in GLSL 1.10) is already done in the lexer.

src/glsl/glsl_lexer.lpp

@@ -151,9 +151,9 @@ ivec4		return IVEC4;
 vec2		return VEC2;
 vec3		return VEC3;
 vec4		return VEC4;
-mat2		return MAT2;
-mat3		return MAT3;
-mat4		return MAT4;
+mat2		return MAT2X2;
+mat3		return MAT3X3;
+mat4		return MAT4X4;
 mat2x2		TOKEN_OR_IDENTIFIER(120, MAT2X2);
 mat2x3		TOKEN_OR_IDENTIFIER(120, MAT2X3);
 mat2x4		TOKEN_OR_IDENTIFIER(120, MAT2X4);

src/glsl/glsl_parser.ypp

@@ -80,7 +80,7 @@
 %token ATTRIBUTE CONST_TOK BOOL FLOAT INT UINT
 %token BREAK CONTINUE DO ELSE FOR IF DISCARD RETURN SWITCH CASE DEFAULT
 %token BVEC2 BVEC3 BVEC4 IVEC2 IVEC3 IVEC4 UVEC2 UVEC3 UVEC4 VEC2 VEC3 VEC4
-%token MAT2 MAT3 MAT4 CENTROID IN OUT INOUT UNIFORM VARYING
+%token CENTROID IN OUT INOUT UNIFORM VARYING
 %token NOPERSPECTIVE FLAT SMOOTH
 %token MAT2X2 MAT2X3 MAT2X4
 %token MAT3X2 MAT3X3 MAT3X4
@@ -1101,9 +1101,6 @@ basic_type_specifier_nonarray:
 	| UVEC2			{ $$ = ast_uvec2; }
 	| UVEC3			{ $$ = ast_uvec3; }
 	| UVEC4			{ $$ = ast_uvec4; }
-	| MAT2			{ $$ = ast_mat2; }
-	| MAT3			{ $$ = ast_mat3; }
-	| MAT4			{ $$ = ast_mat4; }
 	| MAT2X2		{ $$ = ast_mat2; }
 	| MAT2X3		{ $$ = ast_mat2x3; }
 	| MAT2X4		{ $$ = ast_mat2x4; }