ForbidCheckedExceptionInYieldingMethod: skip closures handled by callable rule

[janedbal]

Summary

Alternative implementation for #349 (closes #346) — extracts a shared ImmediatelyInvokedCallableHelper instead of duplicating the reflection/argument analysis logic.

• New ImmediatelyInvokedCallableHelper — shared service encapsulating reflection resolution, ArgumentsNormalizer dispatch, isImmediatelyInvokedCallable check, and isCallableExpression detection
• Refactored ForbidCheckedExceptionInCallableRule — removed 5 duplicated methods (~116 lines), whitelistAllowedCallables now delegates to the helper
• Fixed ForbidCheckedExceptionInYieldingMethodRule — only reports yielding closures that are @param-immediately-invoked-callable or directly invoked; non-immediately-invoked and standalone closures are left to ForbidCheckedExceptionInCallableRule

Why not just merge #349?

PR #349 solves the problem correctly but duplicates ~80 lines of reflection/argument analysis logic from the callable rule. This creates a maintenance burden — any PHPStan API change (like the fiber processing change in #340) would require identical fixes in both rules.

Improvements over #349

• Zero duplication — single point of maintenance for the shared logic
• Yielding rule is 145 lines vs 245 in ForbidCheckedExceptionInYieldingMethod: skip closures handled by callable rule #349
• Includes proper getParameterIndex support for named args when ArgumentsNormalizer fallback kicks in
• Includes NullsafeMethodCall handling in isCallableExpression

Test plan

• All 63 existing tests pass (896 assertions)
• PHPStan self-analysis clean
• New test cases: non-immediately-invoked closure (no error), named arg to immediately-invoked (error), standalone closure (no error), directly invoked closure (error)

Co-Authored-By: Claude Code