message: Add unit test for calling system functions without parentheses
diff: @@ -3426,7 +3426,7 @@ static constexpr FormatterTestCase kFormatterTestCases[] = {
  " input bit [7:0] data_i [],\n"
  " output bit [7:0] data_o []\n"
  ");\n"},
  - {// module with system task call
  + {// module with system task call w or w/o parentheses
  "module m; initial begin #10 $display(\"foo\"); $display(\"bar\");"
  "end endmodule",
  "module m;\n"
  @@ -3435,6 +3435,15 @@ static constexpr FormatterTestCase kFormatterTestCases[] = {
  " $display(\"bar\");\n"
  " end\n"
  "endmodule\n"},
  + {// module with system task call
  + "module m; initial begin #10 $display; $display;"
  + "end endmodule",
  + "module m;\n"
  + " initial begin\n"
  + " #10 $display;\n"
  + " $display;\n"
  + " end\n"
  + "endmodule\n"},
  // interface test cases
  {// two interface declarations
  