[RISC-V] .insn directive does not support constant arg

[charlie-rivos]

GNU-as supports a constant value to the .insn assembler directive as of commit: bminor/binutils-gdb@a262b82. The RISC-V LLVM assembler currently only supports the .insn directive with in the form of .insn <type>, <operand1>, <operand2>. Can the form of .insn <value> also be supported by Clang?

[llvmbot]

@llvm/issue-subscribers-backend-risc-v

Author: None (charlie-rivos)

GNU-as supports a constant value to the .insn assembler directive as of commit: https://github.com/bminor/binutils-gdb/commit/a262b82fdbf4cda3b0648b1adc32245ca3f78b7a. The RISC-V LLVM assembler currently only supports the .insn directive with in the form of `.insn <type>, <operand1>, <operand2>`. Can the form of `.insn <value>` also be supported by Clang?

[lenary]

These are in a PR against the asm manual, but it hasn't landed yet: riscv-non-isa/riscv-asm-manual#106

[charlie-rivos]

I will push that through first then, thank you!