Handle function arguments inside function calls.

test/splitting/function_arguments.stmt

 40 columns                              |
 >>> args before and after function do not force nesting
 method(first,() {fn;},third);
 <<<
 method(first, () {
   fn;
 }, third);
 >>> nothing but function args does not nest
 longFunctionName(() {;}, () {;}, () {;});
 <<<
@@ skipping 119 matching lines @@
 >>> functions with named arguments
 longFunctionName(() {;}, a: () {;}, b: () {;});
 <<<
 longFunctionName(() {
   ;
 }, a: () {
   ;
 }, b: () {
   ;
 });
->>> don't nest because of nested 1-arg fn
+>>> do not nest because of nested 1-arg fn
 outer(inner(() {body;}));
 <<<
 outer(inner(() {
   body;
 }));
->>> do nest because of nested many-arg fn
+>>> do not nest because of nested many-arg fn
 outer(argument, inner(() {body;}));
 <<<
-outer(
-    argument,
-    inner(() {
-      body;
-    }));
->>> don't nest because of nested 1-arg method call
-obj.outer(obj.inner(() {body;}));
-<<<
-obj.outer(obj.inner(() {
+outer(argument, inner(() {
   body;
 }));
->>> do nest because of nested many-arg method call
-obj.outer(argument, obj.inner(() {body;}));
+>>> do not nest because of nested 1-arg method call
+obj.outer(a.b.c.fn(() {body;}));
 <<<
-obj.outer(
-    argument,
-    obj.inner(() {
-      body;
-    }));
+obj.outer(a.b.c.fn(() {
+  body;
+}));
+>>> do not nest because of nested many-arg method call
+obj.outer(argument, a.b.c.fn(() {body;}));
+<<<
+obj.outer(argument, a.b.c.fn(() {
+  body;
+}));
 >>> do not force named args to split on positional function
 function(argument, () {;},
     named: argument, another: argument);
 <<<
 function(argument, () {
   ;
 }, named: argument, another: argument);
 >>> args before and after functions split independently
 longFunction(argument, argument, argument, argument, argument,
 () {;}, () {;}, argument, argument, argument, argument, argument);
 <<<
 longFunction(argument, argument,
     argument, argument, argument, () {
   ;
 }, () {
   ;
 }, argument, argument, argument,
     argument, argument);