`asm_experimental_arch`

The tracking issue for this feature is: #133416

This tracks support for additional registers in architectures where inline assembly is already stable.

Register classes

Architecture	Register class	Registers	LLVM constraint code

Architecture	Register class	Target feature	Allowed types
x86	`xmm_reg`	`sse`	`i128`
x86	`ymm_reg`	`avx`	`i128`
x86	`zmm_reg`	`avx512f`	`i128`

Architecture	Base register	Aliases

Architecture	Unsupported register	Reason

Architecture	Register class	Modifier	Example output	LLVM modifier