Correctly identify fragment closing brace to allow custom light functions

[Xtarsia]

Shader inserts (Editor functions & debug views) currently find the last " } " in the shader, however this prevents use of a custom light() function.

Identifying the correct " } " fixes this issue.

[TokisanGames]

Looks good. Minor point: This will break if there is no space after a statement's semicolon and the last }:

void fragment() {vec2 uv = UV;}

or

void fragment() {vec2 uv = UV

;}

or

void fragment() {vec2 uv = UV;

int a;}

  333 | void fragment() {vec2 uv = UV;
  334 |
  335 | int a
E 336->  ALBEDO = get_decal(ALBEDO, uv);
  337 |
  338 | ;}
SHADER ERROR: Expected a ',' or ';'.
          at: (null) (:335)

[Xtarsia]

Fixed the idx value adjustment, and it seems to work just fine when that space is missing now as well!

tested with this monstrosity:

also no space at the end, along with every debug view enabled at the same time.

[TokisanGames]

Great work. Thanks!