Arm32 Crossgen2 initial support (#43243)

Arm32 Crossgen2 initial support (#43243)

- Fix type layout bugs
  - Sequential or Explicit layout classes without explicit field offsets on arm32 should align their fields based on the start of the field list of the object
  - The field base offset used for R2R calculation on Arm32 should respect the RequiresAlign8 flag
  - Computing true for requiresAlign8 in auto field layout should set the alignment of a class to 8 during auto layout
  - if a class derives from an type which requires 8 byte alignment, set the derived to require higher alignment
- Align the EH info table on 4 byte boundaries
- Set the thumb bit on the arm32 personality routine RVA in XData
- Enable Crossgen2 smoke test for arm
- Adjust architecture specific type layout tests to match CoreCLR behavior
- Fix alignment of Export functions within PE file