[libc-commits] [libc] [libc][SysMMan] implement mincore (PR #73704)

[Schrodinger ZHU Yifan via libc-commits]

SchrodingerZhu wrote:

@nickdesaulniers tests added. There is another thing: 

> On return, the least significant bit of each byte will be set if the corresponding page is currently resident in memory, and be clear otherwise. (The settings of the other bits in each byte are undefined; these bits are reserved for possible later use.)
       
Hence, I should only check the LSB, which is corrected in my last commit.

https://github.com/llvm/llvm-project/pull/73704