[GlobalISel] Correct constant type in matchReassocConstantInnerLHS

When we match a pattern from m_GCst, the register type could be different from original op. So we can't replace the original op to vreg direct.
This code create a new constant with original op type then replace the original op.

Fix #58906

Reviewed By: arsenm, aemerson

Differential Revision: https://reviews.llvm.org/D137778