* enable DLFCN.
* bump WAMR to a version which i happened to test.
* enable bulk-memory because it's required by recent versions of
wasi-sdk, which i happened to use to build a test module.
(test.wasm in the log below.)
Lightly tested with a stripped down version of WAMR native-lib example. [1]
```
nsh> mount -t littlefs /dev/esp32flash /mnt
nsh> iwasm --native-lib=/mnt/test_add.o /mnt/test.wasm
Hello World!
10 + 20 = 30
nsh> iwasm /mnt/test.wasm
[00:00:23:000 - 6]: warning: failed to link import function (env, test_add)
Hello World!
Exception: failed to call unlinked import function (env, test_add)
nsh>
```
[1] https://github.com/bytecodealliance/wasm-micro-runtime/tree/main/samples/native-lib
fc4493b7f1