MIPS extension support - Loongson additional instructions

[notxvilka]

Feature

• New architecture module
• Support for processor extension
• Add more instruction details (elaborated below)
• Binding support for: language
• Other (elaborated below)

Describe the feature you'd like
Looongson MIPS chips have their own extensions

Additional context

• https://gcc.gnu.org/onlinedocs/gcc/MIPS-Loongson-Built-in-Functions.html
• https://patchew.org/QEMU/20201221110538.3186646-1-chenhuacai@kernel.org/