SPV_EXT_relaxed_printf_string_address_space allows format from too many address spaces

[LU-JOHN]

Using --spirv-ext=+SPV_EXT_relaxed_printf_string_address_space allows printf format strings from any address space, but https://github.com/pjaaskel/SPIRV-Registry/blob/2f4cb5fd64b189f8ab0ddeb770a2b67aade41613/extensions/EXT/SPV_EXT_relaxed_printf_string_address_space.asciidoc states:

"format must be a pointer(constant, global, local, private, generic) to i8."

In particular calls like: %4 = call spir_func i32 @_Z18__spirv_ocl_printfPU3AS1c(ptr addrspace(1) %3) #0 are accepted, but addrspace(1) maps to: ATTR_VOLATILE.