os/linux: workaround for sparcv9

Author: vrischmann

lib/std/os/linux.zig

@@ -1442,7 +1442,10 @@ pub fn fadvise(fd: fd_t, offset: u64, len: u64, advice: usize) usize {
             length_halves[0],
             length_halves[1],
         );
-    } else if (@hasField(SYS, "fadvise64_64")) {
+    } else if (@hasField(SYS, "fadvise64_64") and usize_bits != 64) {
+        // The extra usize check is needed to avoid SPARC64 because it provides both
+        // fadvise64 and fadvise64_64 but the latter behaves differently than other platforms.
+
         const offset_halves = splitValue64(@bitCast(u64, offset));
         const length_halves = splitValue64(@bitCast(u64, len));