Moved the Bit64 constant out of the regfile.hh into isa_traits.cc, which is the only place it was used.
Moved the Bit64 constant out of the regfile.hh into isa_traits.cc, which is the only place it was used.

haowu4682/gem5,haowu4682/gem5,LingxiaoJIA/gem5,LingxiaoJIA/gem5,LingxiaoJIA/gem5,haowu4682/gem5,haowu4682/gem5,andrewfu0325/gem5-aladdin,haowu4682/gem5,LingxiaoJIA/gem5,LingxiaoJIA/gem5,andrewfu0325/gem5-aladdin,LingxiaoJIA/gem5,andrewfu0325/gem5-aladdin,haowu4682/gem5,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,LingxiaoJIA/gem5,haowu4682/gem5,haowu4682/gem5,haowu4682/gem5