[wasm] Initial signal handler

src/v8.gyp

Index: src/v8.gyp
diff --git a/src/v8.gyp b/src/v8.gyp
index bd0a994aadd25db390d31a72badeebda9a07c5ec..1fd7f924a9eba7f0fdb97c47db1f109275f30ead 100644
--- a/src/v8.gyp
+++ b/src/v8.gyp
@@ -1277,7 +1277,10 @@
         'transitions-inl.h',
         'transitions.cc',
         'transitions.h',
+        'trap-handler/handler-outside.cc',
+        'trap-handler/handler-shared.cc',
         'trap-handler/trap-handler.h',
+        'trap-handler/trap-handler-internal.h',
         'type-hints.cc',
         'type-hints.h',
         'type-info.cc',
@@ -1669,6 +1672,9 @@
             'third_party/valgrind/valgrind.h',
           ],
         }],
+        ['v8_target_arch=="x64" and OS=="linux"', {
+            'sources': ['trap-handler/handler-inside.cc']
+        }],
         ['v8_target_arch=="ppc" or v8_target_arch=="ppc64"', {
           'sources': [  ### gcmole(arch:ppc) ###
             'builtins/ppc/builtins-ppc.cc',