[watchos] Add bitcode for armv7k, fix unwind for armv7k

Author: vladimir-ea

compiler/rustc_target/src/spec/armv7k_apple_watchos.rs

@@ -12,6 +12,17 @@ pub fn target() -> Target {
             features: "+v7,+vfp4,+neon".to_string(),
             max_atomic_width: Some(64),
             unsupported_abis: super::arm_base::unsupported_abis(),
+            forces_embed_bitcode: true,
+            // These arguments are not actually invoked - they just have
+            // to look right to pass App Store validation.
+            bitcode_llvm_cmdline: "-triple\0\
+                armv7k-apple-watchos3.0.0\0\
+                -emit-obj\0\
+                -disable-llvm-passes\0\
+                -target-abi\0\
+                darwinpcs\0\
+                -Os\0"
+                .to_string(),
             ..base
         },
     }

library/panic_unwind/src/dwarf/eh.rs

@@ -50,7 +50,7 @@ pub enum EHAction {
 }
 
 pub const USING_SJLJ_EXCEPTIONS: bool =
-    cfg!(all(any(target_os = "ios", target_os = "watchos"), target_arch = "arm"));
+    cfg!(all(target_os = "ios", target_arch = "arm"));
 
 pub unsafe fn find_eh_action(lsda: *const u8, context: &EHContext<'_>) -> Result<EHAction, ()> {
     if lsda.is_null() {

library/unwind/src/libunwind.rs

@@ -240,7 +240,7 @@ if #[cfg(any(target_os = "ios", target_os = "watchos", target_os = "netbsd", not
 } // cfg_if!
 
 cfg_if::cfg_if! {
-if #[cfg(not(all(any(target_os = "ios", target_os = "watchos"), target_arch = "arm")))] {
+if #[cfg(not(all(target_os = "ios", target_arch = "arm")))] {
     // Not 32-bit iOS
     #[cfg_attr(
         all(feature = "llvm-libunwind", any(target_os = "fuchsia", target_os = "linux")),