[wasm-pic] Remove --pass-arg=asyncify-ignore-imports from POSTLINK

Before PIC era, we could assume that the stack is not unwound by
imported functions since all imported functions are WASI syscalls and
they don't use Asyncify at all. However, PIC binary can import functions
from other modules and we cannot guarantee that they won't unwind
the stack.

configure.ac

@@ -1267,7 +1267,7 @@ main()
 [wasi*],[	LIBS="-lm -lwasi-emulated-mman -lwasi-emulated-signal -lwasi-emulated-getpid -lwasi-emulated-process-clocks $LIBS"
 		RUBY_APPEND_OPTIONS(CFLAGS, -D_WASI_EMULATED_SIGNAL -D_WASI_EMULATED_MMAN -D_WASI_EMULATED_GETPID -D_WASI_EMULATED_PROCESS_CLOCKS)
 		RUBY_APPEND_OPTIONS(CPPFLAGS, -D_WASI_EMULATED_SIGNAL -D_WASI_EMULATED_MMAN -D_WASI_EMULATED_GETPID -D_WASI_EMULATED_PROCESS_CLOCKS)
-		POSTLINK="\$(WASMOPT) --asyncify \$(wasmoptflags) --pass-arg=asyncify-ignore-imports -o \$@ \$@${POSTLINK:+; $POSTLINK}"
+		POSTLINK="\$(WASMOPT) --asyncify \$(wasmoptflags) -o \$@ \$@${POSTLINK:+; $POSTLINK}"
 		# wasi-libc's sys/socket.h is not compatible with -std=gnu99,
 		# so re-declare shutdown in include/ruby/missing.h
 		ac_cv_func_shutdown=no