Option to accept unrecognized directives for compatibility with GNU assembly

[tmcintos]

It would be nice to have an option to accept unrecognized directives for compatibility with GNU assembly, for example:

.file "example.c" .option nopic .section .rodata .globl main .type main, @function .size main, .-main .type puts, @function .size puts, .-puts .ident "GCC: (crosstool-NG UNKNOWN) 8.2.0"

This would provide better compatibility with gcc-generated assembly code; e.g. https://godbolt.org/z/tTvkEE