Fix incorrect constant for O_LARGEFILE on mips64-linux-musl

[jam1garner]

Changes O_LARGEFILE from 0 to 0x2000

Bash script used for ensuring constant is correct:

#!/bin/bash
echo "
#include <fcntl.h>
int largefile() {
    return O_LARGEFILE;
}
" | mips64-linux-musl-gcc -c -O2 musl_o_largefile.c -o temp.o
mips64-linux-musl-objdump -d temp.o | grep -A2 largefile

Output:

0000000000000000 <largefile>:
   0:	03e00008 	jr	ra
   4:	24022000 	li	v0,8192    ; 0x2000

Link to relevant portion of kernel source, shows that it should match mips32 musl (which currently has a value of 0x2000 as well).

I believe the reason #2738 had this value incorrect was because it's 0 for glibc on mips64 (to specify it's the default, I believe).

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @Amanieu (or someone else) soon.

Please see the contribution instructions for more information.

[JohnTitor]

Thanks for the detailed explanation, I also confirmed the value on the musl source: https://github.com/bminor/musl/blob/cfdfd5ea3ce14c6abf7fb22a531f3d99518b5a1b/arch/mips64/bits/fcntl.h#L16

cc @Grommish the value is going to be changed as the value is incorrect.

@bors r+

[bors]

📌 Commit 6844aff has been approved by JohnTitor

It is now in the queue for this repository.

[bors]

⌛ Testing commit 6844aff with merge 13e4011...

[bors]

💥 Test timed out

[JohnTitor]

@bors retry

[bors]

⌛ Testing commit 6844aff with merge 1d38aa2...

[bors]

☀️ Test successful - checks-actions, checks-cirrus-freebsd-12, checks-cirrus-freebsd-13, checks-cirrus-freebsd-14
Approved by: JohnTitor
Pushing 1d38aa2 to master...