Unrolled build for #153202

Rollup merge of #153202 - dpaoliello:arm64unwind, r=cuviper

[win] Fix truncated unwinds for Arm64 Windows

Panic backtraces on ARM64 Windows are truncated because Rust's LLVM configuration sets `NoTrapAfterNoreturn = true`, which suppresses the generation of `brk #0x1` (trap) instructions after calls to `noreturn` functions. Without this trap instruction, the return address from a `noreturn` call points past the end of the calling function into an unrelated function, causing `RtlLookupFunctionEntry` to return the wrong unwind information, which terminates the stack walk prematurely.

In general, `NoTrapAfterNoreturn = true` is recommended against for Windows, since we have seen security vulnerabilities in the past where an attacker has managed to return from a noreturn function, or the function wasn't actually noereturn, resulting in executing whatever was after the call.

This change disables setting `NoTrapAfterNoreturn = true` for Windows.

Fixes #140489

Author: rust-timer

compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp

@@ -347,7 +347,13 @@ extern "C" LLVMTargetMachineRef LLVMRustCreateTargetMachine(
     // option causes bugs in the LLVM WebAssembly backend. You should be able to
     // remove this check when Rust's minimum supported LLVM version is >= 18
     // https://github.com/llvm/llvm-project/pull/65876
-    if (!Trip.isWasm()) {
+    //
+    // Also keep traps after noreturn calls on Windows, because the trap is
+    // needed to keep the return address within the calling function's
+    // .pdata range. Without it, RtlLookupFunctionEntry resolves the wrong
+    // function and SEH unwinding (used for backtraces) terminates early.
+    // See https://github.com/rust-lang/rust/issues/140489
+    if (!Trip.isWasm() && !Trip.isOSWindows()) {
       Options.NoTrapAfterNoreturn = true;
     }
   }

tests/ui/runtime/backtrace-debuginfo.rs

@@ -47,14 +47,9 @@ macro_rules! dump_and_die {
         // there, even on i686-pc-windows-msvc. We do the best we can in
         // rust-lang/rust to test it as well, but sometimes we just gotta keep
         // landing PRs.
-        //
-        // aarch64-msvc/arm64ec-msvc is broken as its backtraces are truncated.
-        // See https://github.com/rust-lang/rust/issues/140489
         if cfg!(any(target_os = "android",
                     all(target_os = "linux", target_arch = "arm"),
                     all(target_env = "msvc", target_arch = "x86"),
-                    all(target_env = "msvc", target_arch = "aarch64"),
-                    all(target_env = "msvc", target_arch = "arm64ec"),
                     target_os = "freebsd",
                     target_os = "dragonfly",
                     target_os = "openbsd")) {