jextract: Implement Java-side integer overflow checks for FFM mode (#517)

[DPrakashhh]

Description
Summary: This PR aligns FFM mode with JNI by moving integer validation to the Java side. This prevents native crashes by catching out-of-range values before they reach Swift.

Key Changes
1-Java-Side Validation: Moved range checks from native thunks to Java wrappers using a shared ArithmeticException helper.
2-Type Widening: Parameters (e.g., Int8/16/32) are now widened in Java to allow safe bounds checking against Swift's target limits.
3-Unsigned Handling: Added specific checks to bridge the gap between Java's signed types and Swift's UInt types.
4-Updated Tests: Adjusted "golden" expectations for UnsignedNumberTests, MethodImportTests, and others to reflect new safety logic.

Verification
1-Full Suite: All 201 tests passed across 41 suites.
2-Toolchain: Verified on JDK 25 and Swift 6.2.1.

[DPrakashhh]

I’ve updated the logic to use the new SwiftValueLayout.has32bitSwiftInt helper as suggested. I also included some minor formatting/indentation fixes to keep the generated code consistent.

Please let me know if you’d prefer the formatting changes removed; otherwise, the logic is ready for another look!

Sir, its ready for another look :)

[ktoso]

That's a lot of unrelated changes, may I ask if you're using some agent to write these changes? It makes it difficult to review, please try to keep changes committed to a minimum so that that they are easier to review.

I ended up sick at a conference just now... I'll review as soon as I'm able to in a few days

[DPrakashhh]

I am closing this PR - ig starting a new one will be better after all this mess :/

Closing this in favor of a fresh, clean PR with the has32bitSwiftInt helper and refined signed/unsigned logic. New PR is here: #549