glsl: add has_implicit_conversions()-helper

This makes the code a bit easier to read, as well as will reduce
repetition when we add support for EXT_shader_implicit_conversions.

Signed-off-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Reviewed-by: Tapani Pälli <tapani.palli@intel.com>

src/compiler/glsl/ast_to_hir.cpp

@@ -315,7 +315,7 @@ apply_implicit_conversion(const glsl_type *to, ir_rvalue * &from,
       return true;
 
    /* Prior to GLSL 1.20, there are no implicit conversions */
-   if (!state->is_version(120, 0))
+   if (!state->has_implicit_conversions())
       return false;
 
    /* From page 27 (page 33 of the PDF) of the GLSL 1.50 spec:

src/compiler/glsl/glsl_parser_extras.h

@@ -344,6 +344,11 @@ struct _mesa_glsl_parse_state {
       return ARB_bindless_texture_enable;
    }
 
+   bool has_implicit_conversions() const
+   {
+      return is_version(120, 0);
+   }
+
    void process_version_directive(YYLTYPE *locp, int version,
                                   const char *ident);