fixes#25724
This pull request introduces a small but important fix in the compiler
and adds a new test case related to iterators. The main change in the
compiler ensures that lambda-like constructs are handled consistently
with other procedure definitions, while the new test in the suite covers
a previously untested scenario.
**Compiler improvements:**
* Updated `introduceNewLocalVars` in `compiler/transf.nim` to handle all
`nkLambdaKinds` in addition to `nkProcDef`, `nkFuncDef`, `nkMethodDef`,
and `nkConverterDef`, ensuring consistent transformation of all
lambda-like constructs.
**Testing:**
* Added a block to `tests/iter/titer_issues.nim` to test iterator
behavior in both compile-time and run-time contexts, addressing bug
#25724.
(cherry picked from commit 6353c4e5b0)
68bcee04a1