Fix Mac cmake build for dawn.node

When I build this in the node-webgpu repo and run the tests in that
repo I get this error

`out/cmake-release/gen/node/NapiSymbols.h:26: UNREACHABLE:
napi_create_string_utf8() napi_create_string_utf8 is a weak stub,
and should have been runtime replaced by the node implementation`

Fixed by updating the CMake configuration to match the GN build logic.

Bug: 493513159
Fixes: 493513159
Change-Id: I3091fd8a9dd6c192e5b6bece3ddf0ef9226ffb75
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/297815
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Commit-Queue: Antonio Maiorano <amaiorano@google.com>
Auto-Submit: Gregg Tavares <gman@chromium.org>

src/dawn/node/CMakeLists.txt

diff --git a/src/dawn/node/CMakeLists.txt b/src/dawn/node/CMakeLists.txt
index 374dbb2..f28474b 100644
--- a/src/dawn/node/CMakeLists.txt
+++ b/src/dawn/node/CMakeLists.txt
@@ -179,6 +179,10 @@
     string(REPLACE ";" "" NAPI_SYMBOLS "${NAPI_SYMBOLS}")
     file(GENERATE OUTPUT "${NAPI_SYMBOLS_H}" CONTENT "${NAPI_SYMBOLS}")
     target_sources(dawn_node PRIVATE "NapiSymbols.cpp")
+    target_compile_definitions(dawn_node PRIVATE "NAPI_SYMBOL_WEAK_DECL_ONLY")
+    if (APPLE)
+        target_link_options(dawn_node PRIVATE "-Wl,-undefined,dynamic_lookup")
+    endif()
 endif()
 
 macro(javascript file)