Some suggestions for implementing zilsd extensions in binutils

[dongyasun]

Hi，
The support for binutils（https://github.com/nxp-auto-tools/binutils_zilsd/tree/zilsd） seems to lack recognition of the zilsd extension. And the Zcmlsd(c.ld, c.sd, c.ldsp, c.sdsp) extension does not seem to be supported yet?

[dongyasun]

Hi @christian-herber-nxp
Here is our binutils support for zilsd & zcmlsd(riscv-mcu/riscv-binutils-gdb@a046e86). We hope it can help you with your work and we also hope you can give us some suggestions on what is wrong so that we can make subsequent changes. Looking forward to your reply.

[christian-herber-nxp]

@dongyasun thanks for your suggestions. We will keep working on our end and try to improve. In the meanwhile, we are also open for PRs.
I see that your GCC version is a bit older. We try to work with recent versions of gcc/binutils

[christian-herber-nxp]

our binutils support was updated based on your suggestions. thanks a lot