[builtins] Write __divmoddi4/__divmodsi4 in terms __udivmod instead of __div and multiply.

Previously we calculating the remainder by multiplying the
quotient and divisor and subtracting from the dividend.

__udivmod can calculate the remainder while calculating the
quotient. We just need to correct the sign afterward.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D87433