fix(ecma): indent single-line if statements (#6846)

Fixes #5898.

tests/indent/ecma/if_else.js

@@ -11,3 +11,9 @@ if (cond1) {
 } else {
   do_fallback()
 }
+
+if (true)
+  console.log('hi')
+console.log('hi')
+
+if (true)

tests/indent/javascript_spec.lua

@@ -75,6 +75,8 @@ describe("indent JavaScript:", function()
       { 9, 2 },
       { 12, 2 },
       { 13, 0 },
+      { 16, 0 },
+      { 19, 2 },
     } do
       run:new_line("ecma/if_else.js", { on_line = info[1], text = "hello()", indent = info[2] }, info[3], info[4])
     end