Add compiler-rt fallbacks for sync builtins on armv5te-musl.

Author: Alexhuszagh

build.rs

@@ -356,27 +356,32 @@ mod c {
             }
         }
 
-        if llvm_target[0] == "armv7" {
+        if matches!(llvm_target[0].as_str(), "armv5te" | "armv7") {
             sources.extend(&[
                 ("__sync_fetch_and_add_4", "arm/sync_fetch_and_add_4.S"),
-                ("__sync_fetch_and_add_8", "arm/sync_fetch_and_add_8.S"),
                 ("__sync_fetch_and_and_4", "arm/sync_fetch_and_and_4.S"),
-                ("__sync_fetch_and_and_8", "arm/sync_fetch_and_and_8.S"),
                 ("__sync_fetch_and_max_4", "arm/sync_fetch_and_max_4.S"),
-                ("__sync_fetch_and_max_8", "arm/sync_fetch_and_max_8.S"),
                 ("__sync_fetch_and_min_4", "arm/sync_fetch_and_min_4.S"),
-                ("__sync_fetch_and_min_8", "arm/sync_fetch_and_min_8.S"),
                 ("__sync_fetch_and_nand_4", "arm/sync_fetch_and_nand_4.S"),
-                ("__sync_fetch_and_nand_8", "arm/sync_fetch_and_nand_8.S"),
                 ("__sync_fetch_and_or_4", "arm/sync_fetch_and_or_4.S"),
-                ("__sync_fetch_and_or_8", "arm/sync_fetch_and_or_8.S"),
                 ("__sync_fetch_and_sub_4", "arm/sync_fetch_and_sub_4.S"),
-                ("__sync_fetch_and_sub_8", "arm/sync_fetch_and_sub_8.S"),
                 ("__sync_fetch_and_umax_4", "arm/sync_fetch_and_umax_4.S"),
-                ("__sync_fetch_and_umax_8", "arm/sync_fetch_and_umax_8.S"),
                 ("__sync_fetch_and_umin_4", "arm/sync_fetch_and_umin_4.S"),
-                ("__sync_fetch_and_umin_8", "arm/sync_fetch_and_umin_8.S"),
                 ("__sync_fetch_and_xor_4", "arm/sync_fetch_and_xor_4.S"),
+            ]);
+        }
+
+        if llvm_target[0] == "armv7" {
+            sources.extend(&[
+                ("__sync_fetch_and_add_8", "arm/sync_fetch_and_add_8.S"),
+                ("__sync_fetch_and_and_8", "arm/sync_fetch_and_and_8.S"),
+                ("__sync_fetch_and_max_8", "arm/sync_fetch_and_max_8.S"),
+                ("__sync_fetch_and_min_8", "arm/sync_fetch_and_min_8.S"),
+                ("__sync_fetch_and_nand_8", "arm/sync_fetch_and_nand_8.S"),
+                ("__sync_fetch_and_or_8", "arm/sync_fetch_and_or_8.S"),
+                ("__sync_fetch_and_sub_8", "arm/sync_fetch_and_sub_8.S"),
+                ("__sync_fetch_and_umax_8", "arm/sync_fetch_and_umax_8.S"),
+                ("__sync_fetch_and_umin_8", "arm/sync_fetch_and_umin_8.S"),
                 ("__sync_fetch_and_xor_8", "arm/sync_fetch_and_xor_8.S"),
             ]);
         }