Merge branch 'weak-symbols' into 'master'

Weak symbols

See merge request redox-os/relibc!260

src/header/dlfcn/mod.rs

@@ -108,9 +108,9 @@ pub unsafe extern "C" fn dlsym(handle: *mut c_void, symbol: *const c_char) -> *m
         eprintln!("dlsym: linker_ptr: {:p}", tcb.linker_ptr);
         let linker = (&*tcb.linker_ptr).lock();
 
-        if let Some(global) = linker.globals.get(symbol_str) {
-            eprintln!("dlsym({:p}, {}) = 0x{:x}", handle, symbol_str, *global);
-            *global as *mut c_void
+        if let Some(global) = linker.get_sym(symbol_str) {
+            eprintln!("dlsym({:p}, {}) = 0x{:x}", handle, symbol_str, global);
+            global as *mut c_void
         } else {
             eprintln!("dlsym: symbol not found");
             ERROR.store(ERROR_NOT_SUPPORTED.as_ptr() as usize, Ordering::SeqCst);

src/header/unistd/mod.rs

@@ -5,7 +5,8 @@ use core::{convert::TryFrom, mem, ptr, slice};
 use crate::{
     c_str::CStr,
     header::{
-        errno, fcntl, limits, stdlib::getenv, sys_ioctl, sys_time, sys_utsname, termios, time::timespec,
+        errno, fcntl, limits, stdlib::getenv, sys_ioctl, sys_time, sys_utsname, termios,
+        time::timespec,
     },
     platform::{self, types::*, Pal, Sys},
 };