Function overload check cleanup. Added if statement to parsing.

test/custom_hint.ink

@@ -0,0 +1,12 @@
+p :: properties {
+	time : float @time;
+}
+
+vertex main :: (pos : float3 @position) -> float4 @position {
+	return float4(pos.x, pos.y, pos.z, 1.0);
+}
+
+pixel main :: (pos : float4 @outposition) -> float4 @target {
+	t := p.time;
+	return float4(1, 1, 1, 1);
+}