[clang] [llvm] [RISCV] Support resumable non-maskable interrupt handlers (PR #148134)

[Sam Elliott via llvm-commits]

lenary wrote:

This needs a proposal against the specification here: https://github.com/riscv-non-isa/riscv-c-api-doc/blob/main/src/c-api.adoc#__attribute__interrupt-__attribute__interruptsupervisor-__attribute__interruptmachine 



https://github.com/llvm/llvm-project/pull/148134