musl: Fix O_LARGEFILE constant value.

This was accidentally set to 0 in upstream, but fixed in commit b8b729b.
If running with prior versions without that commit, this commit
effectively backports it.

(backport <rust-lang#4443>)
(cherry picked from commit 686aa7a)

Author: xbjfk

libc-test/build.rs

@@ -4329,6 +4329,10 @@ fn test_linux(target: &str) {
             {
                         return true;
             }
+            // Values changed in newer musl versions on these arches
+            if old_musl && (riscv64 || x86_64) && name == "O_LARGEFILE" {
+                return true;
+            }
         }
         match name {
             // These constants are not available if gnu headers have been included

src/unix/linux_like/linux/musl/b64/riscv64/mod.rs

@@ -432,7 +432,7 @@ pub const SYS_landlock_restrict_self: c_long = 446;
 pub const O_APPEND: c_int = 1024;
 pub const O_DIRECT: c_int = 0x4000;
 pub const O_DIRECTORY: c_int = 0x10000;
-pub const O_LARGEFILE: c_int = 0;
+pub const O_LARGEFILE: c_int = 0o100000;
 pub const O_NOFOLLOW: c_int = 0x20000;
 pub const O_CREAT: c_int = 64;
 pub const O_EXCL: c_int = 128;

src/unix/linux_like/linux/musl/b64/x86_64/mod.rs

@@ -701,7 +701,7 @@ pub const MAP_32BIT: c_int = 0x0040;
 pub const O_APPEND: c_int = 1024;
 pub const O_DIRECT: c_int = 0x4000;
 pub const O_DIRECTORY: c_int = 0x10000;
-pub const O_LARGEFILE: c_int = 0;
+pub const O_LARGEFILE: c_int = 0o0100000;
 pub const O_NOFOLLOW: c_int = 0x20000;
 pub const O_CREAT: c_int = 64;
 pub const O_EXCL: c_int = 128;