Delete simple unused vars2 (#23491)

Delete simple unused vars2 (#23491)

* Clean `valuenum.cpp`.

* Clean `emitarm64.cpp`.

* Clean `lsraarm64.cpp`.

* Clean `lsraarmarch.cpp`.

* Clean `lowerarmarch.cpp`.

* Clean `lower.cpp`.

* Clean `ssabuilder.cpp`.

* Clean `simd.cpp`.

* Clear `simdcodegenxarch.cpp`.

* Clean `lowerxarch.cpp`.

* Clean `scopeinfo.cpp`.