meson: propagate optimization flag for linking on Emscripten

Signed-off-by: Kohei Tokunaga <[email protected]>

Author: ktock

meson.build

@@ -397,6 +397,9 @@ elif host_os == 'emscripten'
   if cpu == 'wasm64'
     qemu_ldflags += ['-sMEMORY64=' + get_option('wasm64_memory64')]
   endif
+  if get_option('optimization') != 'plain'
+    qemu_ldflags += ['-O' + get_option('optimization')]
+  endif
 endif
 
 # Choose instruction set (currently x86-only)