Revert "[clang][Interp][NFC] Remove shift error checking code duplication"

This reverts commit fddf6418.

Apparently this also breaks some builders:

/usr/bin/ld: EvalEmitter.cpp:(.text._ZN5clang6interp11EvalEmitter7emitShlENS0_8PrimTypeES2_RKNS0_10SourceInfoE+0x1f54): undefined reference to `bool clang::interp::CheckShift<clang::interp::Integral<16u, true> >(clang::interp::InterpState&, clang::interp::CodePtr, clang::interp::Integral<16u, true> const&, unsigned int)'
/usr/bin/ld: EvalEmitter.cpp:(.text._ZN5clang6interp11EvalEmitter7emitShlENS0_8PrimTypeES2_RKNS0_10SourceInfoE+0x1fd4): undefined reference to `bool clang::interp::CheckShift<clang::interp::Integral<32u, true> >(clang::interp::InterpState&, clang::interp::CodePtr, clang::interp::Integral<32u, true> const&, unsigned int)'
/usr/bin/ld: EvalEmitter.cpp:(.text._ZN5clang6interp11EvalEmitter7emitShlENS0_8PrimTypeES2_RKNS0_10SourceInfoE+0x2058): undefined reference to `bool clang::interp::CheckShift<clang::interp::Integral<32u, true> >(clang::interp::InterpState&, clang::interp::CodePtr, clang::interp::Integral<32u, true> const&, unsigned int)'

(etc)