add a Windows GNU AVX-512 build break workaround

The break in question only repros under --release, and we didn't start
testing a release build of the prefer-intrinsics mode until just now.

1 files changed, 4 insertions, 0 deletions

diff --git a/build.rs b/build.rs
index 8d74f04..b7f7f7b 100644
--- a/build.rs
+++ b/build.rs
@@ -148,6 +148,10 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
                 avx512_build.flag("-mavx512f");
                 avx512_build.flag("-mavx512vl");
             }
+            if is_windows_gnu() {
+                // Workaround for https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65782.
+                avx512_build.flag("-fno-asynchronous-unwind-tables");
+            }
             avx512_build.compile("blake3_avx512");
         } else {
             // Currently no effect for non-x86 platforms.