Fix accidental fall-through in Flow type parsing. (#82)

When parsing a primary type, `>` would erroneously be treated like `(`.

src/plugins/flow.js

@@ -506,6 +506,7 @@ pp.flowParsePrimaryType = function () {
 
         return this.finishNode(node, "FunctionTypeAnnotation");
       }
+      break;
 
     case tt.parenL:
       this.next();

test/fixtures/flow/type-annotations/106/actual.js

@@ -0,0 +1 @@
+var f: >x:int) => string;

test/fixtures/flow/type-annotations/106/options.json

@@ -0,0 +1,3 @@
+{
+  "throws": "Unexpected token (1:7)"
+}