[InstCombine] Support vectors in SimplifyAddWithRemainder.
SimplifyAddWithRemainder currently also matches for vector types, but
tries to create an integer constant, which causes a crash.
By using Constant::getIntegerValue() we can support both the scalar and
The 2 added test cases crash without the fix.
Reviewers: spatel, lebedev.ri
Reviewed By: spatel, lebedev.ri
Differential Revision: https://reviews.llvm.org/D75906