[COFF, ARM64] Set the data type widths and the data layout string

Summary: COFF ARM64 is LLP64 platform. So int is 4 bytes, long is 4 bytes and long long is 8 bytes.

Reviewers: compnerd, ruiu, rnk, efriedma

Reviewed By: compnerd, efriedma

Subscribers: efriedma, javed.absar, cfe-commits, aemerson, llvm-commits, kristof.beyls

Differential Revision: https://reviews.llvm.org/D34859

llvm-svn: 308222