This currently doesn't work with ASan, but I have an open issue for this
here: bdwgc/bdwgc#772

It leaks, leads to premature GC, takes too long to compile, and doesn't
support runtime sorting functions. We'll need a new solution.

For now, we're deep copying standard containers, which isn't going to
last us very long.

This addresses a GC crash we were seeing, as documented here: bdwgc/bdwgc#800 (comment)

It's blocked on this Clang bug: llvm/llvm-project#146956

**Object Slicing Prevention (lines 2766-2783)**
- Added automatic promotion of C++ class/struct catch types to lvalue references
- Prevents object slicing when catching derived classes by base type
- Preserves polymorphic behavior (virtual methods work correctly)
- Exception: jank::runtime types (like object_ref) remain by-value (needs to figure out why)

**Duplicate Catch Detection (lines 2785-2796)**
- Added compile-time validation to detect duplicate catch clauses

**Fixed Pointer Exception Handling (lines 1797-1826)**
- Corrected exception value extraction for pointer types
- Pointer exceptions: Use caught_ptr directly (it IS the pointer value)
- Non-pointer exceptions: Dereference caught_ptr to get the value
- Fixes crashes when catching void*, int*, and other pointer types
- Added support for reference types and class/struct types

**Enhanced Load Detection (line 543)**
- Extended auto-load logic to handle pointer and reference types
- Ensures proper value extraction from alloca instructions