intel/compiler: Handle invalid inputs to brw_reg_type_to_*()

Necessary to handle these cases when we test fuzzed instructions.

Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/2635>

src/intel/compiler/brw_reg_type.c

@@ -479,6 +479,9 @@ brw_reg_type_to_size(enum brw_reg_type type)
       [BRW_REGISTER_TYPE_V]  = 2,
       [BRW_REGISTER_TYPE_UV] = 2,
    };
+   if (type >= ARRAY_SIZE(type_size))
+      return -1;
+
    return type_size[type];
 }
 
@@ -509,6 +512,9 @@ brw_reg_type_to_letters(enum brw_reg_type type)
       [BRW_REGISTER_TYPE_V]  = "V",
       [BRW_REGISTER_TYPE_UV] = "UV",
    };
+   if (type >= ARRAY_SIZE(letters))
+      return "INVALID";
+
    assert(type < ARRAY_SIZE(letters));
    return letters[type];
 }