nir: Add a glsl_vec_type() helper.

I need access to glsl_type::vec2_type from C.  Wrapping vec() also gives
us access to vec3 if we need it.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

src/glsl/nir/nir_types.cpp

@@ -167,6 +167,12 @@ glsl_float_type(void)
    return glsl_type::float_type;
 }
 
+const glsl_type *
+glsl_vec_type(unsigned n)
+{
+   return glsl_type::vec(n);
+}
+
 const glsl_type *
 glsl_vec4_type(void)
 {

src/glsl/nir/nir_types.h

@@ -75,6 +75,7 @@ bool glsl_type_is_matrix(const struct glsl_type *type);
 
 const struct glsl_type *glsl_void_type(void);
 const struct glsl_type *glsl_float_type(void);
+const struct glsl_type *glsl_vec_type(unsigned n);
 const struct glsl_type *glsl_vec4_type(void);
 const struct glsl_type *glsl_uint_type(void);
 const struct glsl_type *glsl_array_type(const struct glsl_type *base,