[wasm2c] catching traps without exception runtime

[whirlicote]

I was trying out wasm_rt_impl_try from the wasm-rt-impl.h header when I got the following error:

src/wasm-rt-impl.h:59:32: error: 'wasm_rt_set_unwind_target' was not declared in this scope
   59 |   (WASM_RT_SAVE_STACK_DEPTH(), wasm_rt_set_unwind_target(&g_wasm_rt_jmp_buf), \
      |                                ^~~~~~~~~~~~~~~~~~~~~~~~~
src/gdexample.cpp:110:25: note: in expansion of macro 'wasm_rt_impl_try'
  110 |   wasm_rt_trap_t code = wasm_rt_impl_try();
      |                         ^~~~~~~~~~~~~~~~

Perhaps there is a missing include in wasm-rt-impl.h,

...
#include "wasm-rt-exceptions.h"
...

or perhaps the sample in my code needs to be adapted to something like this?

wasm_rt_trap_t code = wasm_rt_try(g_wasm_rt_jmp_buf);
if (WASM_RT_TRAP_NONE == code) {
  w2c_0x24empty(&my_module);
}
else {
  printf("%s\n", wasm_rt_strerror(code));
}

I would like to avoid explicitly including the exception handling runtime header since my WebAssembly module is not using the exceptions handling extension.