[libunwind][LoongArch] Add 64-bit LoongArch support

Defines enums for the LoongArch registers.
Adds the register class implementation for LoongArch.
Adds save and restore context functionality.

This only supports 64 bits integer and float-point register
implementation.

Fix https://github.com/llvm/llvm-project/issues/55398

Reviewed By: SixWeining

Differential Revision: https://reviews.llvm.org/D137010

NOKEYCHECK=True
GitOrigin-RevId: c5072695127e767a76973cdbed683215df31fa40
8 files changed
tree: c976c799814866a44b373a06608136bce70a63c6
  1. cmake/
  2. docs/
  3. include/
  4. src/
  5. test/
  6. .clang-format
  7. CMakeLists.txt
  8. LICENSE.TXT