diff -up thunderbird-68.0/js/src/wasm/WasmSignalHandlers.cpp.aarch64-user_vfp thunderbird-68.0/js/src/wasm/WasmSignalHandlers.cpp
--- thunderbird-68.0/js/src/wasm/WasmSignalHandlers.cpp.aarch64-user_vfp	2019-09-05 08:57:46.443137916 +0200
+++ thunderbird-68.0/js/src/wasm/WasmSignalHandlers.cpp	2019-09-05 08:58:07.776196823 +0200
@@ -244,7 +244,7 @@ using mozilla::DebugOnly;
 // emulation here.
 
 #if defined(__linux__) && defined(__arm__)
-#  define WASM_EMULATE_ARM_UNALIGNED_FP_ACCESS
+//#  define WASM_EMULATE_ARM_UNALIGNED_FP_ACCESS
 #endif
 
 #ifdef WASM_EMULATE_ARM_UNALIGNED_FP_ACCESS