[Bug #21784] Fix the Proc#source_location start_column for stabby lambdas

* Consistent with plain `blocks` and `for` blocks and methods
  where the source_location covers their entire definition.
* Matches the documentation which mentions
  "where the definition starts/ends".
* Partially reverts d357d50f0a74409446f4cccec78593373f5adf2f
  which was a workaround to be compatible with parse.y.

1 files changed, 1 insertions, 1 deletions

diff --git a/parse.y b/parse.y
index 067f45e6d6..03dd1c6f92 100644
--- a/parse.y
+++ b/parse.y
@@ -5149,7 +5149,7 @@ lambda		: tLAMBDA[lpar]
                         CMDARG_POP();
                         $args = args_with_numbered(p, $args, max_numparam, it_id);
                         {
-                            YYLTYPE loc = code_loc_gen(&@args, &@body);
+                            YYLTYPE loc = code_loc_gen(&@lpar, &@body);
                             $$ = NEW_LAMBDA($args, $body->node, &loc, &@lpar, &$body->opening_loc, &$body->closing_loc);
                             nd_set_line(RNODE_LAMBDA($$)->nd_body, @body.end_pos.lineno);
                             nd_set_line($$, @args.end_pos.lineno);