[mlir][llvm] Import matrix, vector, and assume intrinsics from LLVM IR.

[gysit]

Summary

The revision adds support to import:

• matrix intrinsics
• vector reduce fadd/fmul intrinsics
• assume intrinsics

from LLVM IR.

[ftynse]

While you are looking at these, maybe we can also have more specific type constraints than the generic LLVM_Type?

[gysit]

While you are looking at these, maybe we can also have more specific type constraints than the generic LLVM_Type?

Yes that may actually unveil some import bugs. I'll put it on my TODO list to make the types of at least some of the operation types more precise. It seems like the type definitions are already there!

[ftynse]

Yes, I switched most of the operations to have better type constraints, but didn't do this for intrinsics.

[gysit]

Remove redunant variable name in assume intrinsic declaration.