Try working around the android bug by making sync symbols strong

Author: tgross35

src/arm_linux.rs

@@ -90,11 +90,30 @@ unsafe fn atomic_cmpxchg<T>(ptr: *mut T, oldval: u32, newval: u32) -> u32 {
 
 macro_rules! atomic_rmw {
     ($name:ident, $ty:ty, $op:expr, $fetch:expr) => {
+        #[cfg(not(target_os = "android"))]
         intrinsics! {
             pub unsafe extern "C" fn $name(ptr: *mut $ty, val: $ty) -> $ty {
                 atomic_rmw(ptr, |x| $op(x as $ty, val) as u32, |old, new| $fetch(old, new)) as $ty
             }
         }
+
+        #[cfg(target_os = "android")]
+        #[cfg(not(feature = "mangled-names"))]
+        mod $name {
+            #[no_mangle]
+            unsafe extern "C" fn $name(ptr: *mut $ty, val: $ty) -> $ty {
+                super::$name(ptr, val)
+            }
+        }
+
+        #[cfg(target_os = "android")]
+        pub unsafe extern "C" fn $name(ptr: *mut $ty, val: $ty) -> $ty {
+            atomic_rmw(
+                ptr,
+                |x| $op(x as $ty, val) as u32,
+                |old, new| $fetch(old, new),
+            ) as $ty
+        }
     };
 
     (@old $name:ident, $ty:ty, $op:expr) => {
@@ -105,13 +124,29 @@ macro_rules! atomic_rmw {
         atomic_rmw!($name, $ty, $op, |_, new| new);
     };
 }
+
 macro_rules! atomic_cmpxchg {
     ($name:ident, $ty:ty) => {
+        #[cfg(not(target_os = "android"))]
         intrinsics! {
             pub unsafe extern "C" fn $name(ptr: *mut $ty, oldval: $ty, newval: $ty) -> $ty {
                 atomic_cmpxchg(ptr, oldval as u32, newval as u32) as $ty
             }
         }
+
+        #[cfg(target_os = "android")]
+        #[cfg(not(feature = "mangled-names"))]
+        mod $name {
+            #[no_mangle]
+            unsafe extern "C" fn $name(ptr: *mut $ty, oldval: $ty, newval: $ty) -> $ty {
+                super::$name(ptr, oldval, newval)
+            }
+        }
+
+        #[cfg(target_os = "android")]
+        pub unsafe extern "C" fn $name(ptr: *mut $ty, oldval: $ty, newval: $ty) -> $ty {
+            atomic_cmpxchg(ptr, oldval as u32, newval as u32) as $ty
+        }
     };
 }