Golang do not align to open ( or {

Changed the indentation behavior such that an extra level of
indentation is added after a line containing a ( or { that is
not closed on the same line instead of aligning to the unclosed
( or {. This is consistent with how `go fmt` formats source code.

Added regression tests.

rc/filetype/go.kak

@@ -111,10 +111,8 @@ define-command -hidden go-indent-on-new-line %~
                 execute-keys -draft <a-?> /\* <ret> <a-K>\*/<ret>
             }
         } catch %{
-            # indent after lines ending with { or (
-            try %[ execute-keys -draft k<a-x> <a-k> [{(]\h*$ <ret> j<a-gt> ]
-            # align to opening paren of previous line
-            try %{ execute-keys -draft [( <a-k> \A\([^\n]+\n[^\n]*\n?\z <ret> s \A\(\h*.|.\z <ret> '<a-;>' & }
+            # indent after lines with an unclosed { or (
+            try %< execute-keys -draft [c[({],[)}] <ret> <a-k> \A[({][^\n]*\n[^\n]*\n?\z <ret> j<a-gt> >
             # indent after a switch's case/default statements
             try %[ execute-keys -draft k<a-x> <a-k> ^\h*(case|default).*:$ <ret> j<a-gt> ]
             # deindent closing brace(s) when after cursor

test/indent/go/deindent-generic-closing-brace/in

@@ -47,3 +47,9 @@ a := []int{
     someFunction(%( )
     ),
 }
+
+14
+foobar(baz,%( )
+
+15
+foobar{ // some comment%( )

test/indent/go/deindent-generic-closing-brace/out

@@ -63,3 +63,11 @@ a := []int{
         
     ),
 }
+
+14
+foobar(baz,
+    
+
+15
+foobar{ // some comment
+