Upgrade Emscripten targets to use upstream LLVM backend

 - Compatible with Emscripten 1.38.46-upstream or later upstream.
 - Refactors the Emscripten target spec to share code with other wasm
   targets.
 - Replaces the old incorrect wasm32 C call ABI with the correct one,
   preserving the old one as wasm32_bindgen_compat for wasm-bindgen
   compatibility.
 - Updates the varargs ABI used by Emscripten and deletes the old one.
 - Removes the obsolete wasm32-experimental-emscripten target.
 - Uses EMCC_CFLAGS on CI to avoid the timeout problems with #63649.

1 files changed, 3 insertions, 3 deletions

diff --git a/src/libtest/lib.rs b/src/libtest/lib.rs
index 5a77413b2cb..4c3cbeb4acc 100644
--- a/src/libtest/lib.rs
+++ b/src/libtest/lib.rs
@@ -1735,9 +1735,9 @@ pub fn run_test(
 ) {
     let TestDescAndFn { desc, testfn } = test;
 
-    let ignore_because_no_process_support = cfg!(target_arch = "wasm32")
-        && !cfg!(target_os = "emscripten")
-        && desc.should_panic != ShouldPanic::No;
+    // FIXME: Re-enable emscripten once it can catch panics again
+    let ignore_because_no_process_support = desc.should_panic != ShouldPanic::No
+        && (cfg!(target_arch = "wasm32") || cfg!(target_os = "emscripten"));
 
     if force_ignore || desc.ignore || ignore_because_no_process_support {
         monitor_ch.send((desc, TrIgnored, None, Vec::new())).unwrap();