build(wasi): add -fno-lto for __cxa_init_primary_exception

Addresses:

  wasm-ld: warning: function signature mismatch: __cxa_init_primary_exception
  >>> defined as (i32, i32, i32) -> i32 in lto.tmp
  >>> defined as (i32, i32, i32) -> void in libwasi-itk-extras.a(exceptionShim.cxx.o)

Author: thewtex

src/docker/itk-wasm/ITKWebAssemblyInterface.cmake

@@ -64,8 +64,10 @@ function(add_executable target)
     # WASI
     set_property(TARGET ${wasm_target} PROPERTY SUFFIX ".wasi.wasm")
     if (NOT TARGET wasi-itk-extras AND DEFINED CMAKE_CXX_COMPILE_OBJECT)
+      set_source_files_properties(/ITKWebAssemblyInterface/src/exceptionShimInitPrimaryException.cxx PROPERTIES COMPILE_FLAGS "-fno-lto")
       add_library(wasi-itk-extras STATIC
         /ITKWebAssemblyInterface/src/exceptionShim.cxx
+        /ITKWebAssemblyInterface/src/exceptionShimInitPrimaryException.cxx
         /ITKWebAssemblyInterface/src/cxaThreadAtExitShim.cxx
         /ITKWebAssemblyInterface/src/pthreadShim.cxx
         /ITKWebAssemblyInterface/src/initialization.cxx)

src/exceptionShim.cxx

@@ -33,11 +33,6 @@ void __cxa_throw(void *, void *, void *)
   abort();
 }
 
-// Only triggered with Debug wasi-threads builds
-void __cxa_init_primary_exception(void *, void *, void *)
-{
-}
-
 }
 
 #endif // __cplusplus

src/exceptionShimInitPrimaryException.cxx

@@ -0,0 +1,34 @@
+/*=========================================================================
+ *
+ *  Copyright NumFOCUS
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *         https://www.apache.org/licenses/LICENSE-2.0.txt
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *=========================================================================*/
+// Workaround for current lack of exception support
+// Needs separate flags.
+
+#ifdef __cplusplus
+
+#include <stdlib.h>
+
+extern "C" {
+
+// Only triggered with Debug wasi-threads builds
+void __cxa_init_primary_exception(void *, void *, void *)
+{
+}
+
+}
+
+#endif // __cplusplus