[libunwind][RISCV] Make asm statement volatile (#130286)

Compiling with `O3`, the `early-machinelicm` pass hoisted the asm
statement to a path that has been executed unconditionally during stack
unwinding. On hardware without vector extension support, this resulted
in reading a nonexistent register.

GitOrigin-RevId: 3acfef56b1c5f74edd6ea2111a440677ea2c6763
1 file changed
tree: b8baf7811a44067ec3f8acba11521049ac2a84a3
  1. cmake/
  2. docs/
  3. include/
  4. src/
  5. test/
  6. .clang-format
  7. CMakeLists.txt
  8. LICENSE.TXT