[analyzer][NFC][test] Add new RUN line with...

[analyzer][NFC][test] Add new RUN line with support-symbolic-integer-casts=true to expr-inspection.cpp

Added a new run line to bolster gradual transition of handling cast operations,
see https://discourse.llvm.org/t/roadmap-of-modeling-symbolic-cast-operations/63107

Differential Revision: https://reviews.llvm.org/D127649