builtin function as ident is legal. thanks @gre!

Author: chrisdickinson

lib/index.js

@@ -454,7 +454,7 @@ function parser() {
         return stmt.stage + 3
       }
 
-      if(token.type !== 'ident') {
+      if(token.type !== 'ident' && token.type !== 'builtin') {
         return unexpected('expected identifier, got '+token.data)
       }
 

test/test.glsl

@@ -85,3 +85,4 @@ int first, second, third, fourth, fifth, sixth, seventh, eigth;
         continue;
     }
 
+float distance = 1.0;