Use mmap64 on Linux.

mmap is a non-LFS function and due to its usage here will appear in
binaries produced by rustc.

This is relevant to rust-lang/rust#94173.

src/symbolize/gimli/mmap_unix.rs

@@ -4,14 +4,19 @@ use core::ops::Deref;
 use core::ptr;
 use core::slice;
 
+#[cfg(target_os = "linux")]
+use libc::mmap64;
+#[cfg(not(target_os = "linux"))]
+use libc::mmap as mmap64;
+
 pub struct Mmap {
     ptr: *mut libc::c_void,
     len: usize,
 }
 
 impl Mmap {
     pub unsafe fn map(file: &File, len: usize) -> Option<Mmap> {
-        let ptr = libc::mmap(
+        let ptr = mmap64(
             ptr::null_mut(),
             len,
             libc::PROT_READ,