fix(grainfmt): Correct formatting of submodules ending with comments (#2288)

Author: spotandjake

compiler/src/formatting/fmt.re

@@ -3396,6 +3396,7 @@ let print_module_declaration = (fmt, {pmod_name, pmod_stmts, pmod_loc}) => {
              prev =>
                fmt.print_comment_range(
                  fmt,
+                 ~block_end=true,
                  ~lead=space,
                  prev.ptop_loc,
                  enclosing_end_location(pmod_loc),

compiler/test/grainfmt/comments.expected.gr

@@ -660,3 +660,8 @@ let [/*foo */] = 5
 2
 1 /* abc */ /2
 1 /* abc */ / /* xyz */ 2
+
+// Regression for #2287
+module Bar {
+  1 // foo
+}

compiler/test/grainfmt/comments.input.gr

@@ -508,3 +508,9 @@ let [ /*foo */] = 5
 2
 1/* abc *//2
 1/* abc */ / /* xyz */2
+
+
+// Regression for #2287
+module Bar {
+  1 // foo
+}