Added inferred types and missing length function.

test/parse/field_without_type_specifier.golden

@@ -1,4 +1,4 @@
-test/field_without_type_specifier.ink:2,0: error: Expected type specifier after field name.
-    x := 5.0;
-       ^
-
+(program	
+ (fun vertex vs_main
+  [] 
+  (:= x 5)))

test/parse/inferred_types.golden

@@ -0,0 +1,18 @@
+(program	
+ (fun bar -> float
+  [] 
+  (return 5))
+
+ (fun foo -> float
+  [] 
+  (return (bar)))
+
+ (fun vertex vs_main -> float4 (@position)
+  [(:= pos float3 (@position))] 
+  (:= f 2) 
+  (:= i 10) 
+  (= f (foo)) 
+  (:= v2 (float2 2 2)) 
+  (:= v3 (float3 2 2 3)) 
+  (:= v4 (float4 4 5 6 7)) 
+  (return (float4 1 1 1 1))))