[ClangCL] Fix warnings in HLSLExec (microsoft#5690)

1. Missing const when cast pointer. Add const.
2. Negtive shift casted to unsigned.
3. Missing override for override functions. Add override.
4. Remove unused variable/function.
5. Add constructor for TableParameter to workaround unintialized field.
6. RawBufferLdStTestData<int32_t> first field should not have {} when
initialize.
7. memset parameter order which also fixes in
microsoft#4516 by
gongminmin

Author: python3kgae