pub unsafe fn const_literal_from_parts(
        &self,
        pointer: LLVMValueRef,
        size: LLVMValueRef,
    ) -> LLVMValueRef {
        let undef = LLVMGetUndef(self.vector_ty);
        let result = LLVMConstInsertValue(undef, pointer, [POINTER_INDEX].as_mut_ptr(), 1);
        LLVMConstInsertValue(result, size, [SIZE_INDEX].as_mut_ptr(), 1)
    }
Build a constant vector given a `pointer` and `size`.
weld/src/codegen/llvm2/vector.rs