fix field default values

test/cases/class_def/class_derived.tst

@@ -9,9 +9,7 @@ end
 s(:expressions,
   s(:class, :Foo,
     s(:derives, :Object),
-    s(:name, :int),
-    s(:assign,
-      s(:name, :field),
+    s(:field_def, :int, :field,
       s(:int, 3)),
     s(:function, :int,
       s(:name, :func),

test/cases/class_def/class_ops.tst

@@ -13,9 +13,7 @@ s(:expressions,
       s(:parameters,
         s(:parameter, :int, :x)),
       s(:expressions,
-        s(:name, :int),
-        s(:assign,
-          s(:name, :abba),
+        s(:field_def, :int, :abba,
           s(:int, 5)),
         s(:operator, "+",
           s(:name, :abba),

test/cases/function_definition/function_ops.tst

@@ -9,9 +9,7 @@ s(:expressions,
     s(:parameters,
       s(:parameter, :int, :x)),
     s(:expressions,
-      s(:name, :int),
-      s(:assign,
-        s(:name, :abba),
+      s(:field_def, :int, :abba,
         s(:int, 5)),
       s(:operator, "+",
         s(:name, :abba),

test/cases/function_definition/function_return.tst

@@ -9,9 +9,7 @@ s(:expressions,
     s(:parameters,
       s(:parameter, :ref, :n)),
     s(:expressions,
-      s(:name, :int),
-      s(:assign,
-        s(:name, :i),
+      s(:field_def, :int, :i,
         s(:field_access,
           s(:receiver,
             s(:name, :n)),

test/cases/module_def/module_ops.tst

@@ -1,6 +1,6 @@
 module Opers
   int foo(int x)
-    int abba = x + self.index
+    int abba = self.index
     return abba + 5
   end
 end
@@ -12,16 +12,12 @@ s(:expressions,
       s(:parameters,
         s(:parameter, :int, :x)),
       s(:expressions,
-        s(:name, :int),
-        s(:assign,
-          s(:name, :abba),
-          s(:operator, "+",
-            s(:name, :x),
-            s(:field_access,
-              s(:receiver,
-                s(:name, :self)),
-              s(:field,
-                s(:name, :index))))),
+        s(:field_def, :int, :abba,
+          s(:field_access,
+            s(:receiver,
+              s(:name, :self)),
+            s(:field,
+              s(:name, :index)))),
         s(:return,
           s(:operator, "+",
             s(:name, :abba),

test/cases/root/module_method.tst

@@ -15,9 +15,7 @@ s(:expressions,
       s(:parameters,
         s(:parameter, :int, :n)),
       s(:expressions,
-        s(:name, :int),
-        s(:assign,
-          s(:name, :a),
+        s(:field_def, :int, :a,
           s(:int, 0)),
         s(:return,
           s(:name, :a)))),