wasi: address coverity warning

[mhdawson]

• add check for case when trying to provide a better Exception fails
• the code was modified to avoid a CHECK_EQ in all cases in wasi: throw on failed uvwasi_init() #31076, however, I believe that if we fail to create the exeption to throw instead of simply returning using a CHECK makes more sense. I think it should also address the coverity warning about not initializing in the constructor.

[nodejs-github-bot]

Review requested:

• @nodejs/wasi

[mhdawson]

Coverity warning:

 84  if (err != UVWASI_ESUCCESS) {
 85    Local<Value> exception;
   	2. Condition !v8::MaybeLocal<v8::Value>(node::wasi::WASIException(env->context(), err, "uvwasi_init")).ToLocal(&exception), taking true branch.
 86    if (!WASIException(env->context(), err, "uvwasi_init").ToLocal(&exception))
   	4. uninit_member: Non-static class member uvw_.fds is not initialized in this constructor nor in any functions that it calls.
   	6. uninit_member: Non-static class member uvw_.argc is not initialized in this constructor nor in any functions that it calls.
   	8. uninit_member: Non-static class member uvw_.argv is not initialized in this constructor nor in any functions that it calls.
   	10. uninit_member: Non-static class member uvw_.argv_buf is not initialized in this constructor nor in any functions that it calls.
   	12. uninit_member: Non-static class member uvw_.argv_buf_size is not initialized in this constructor nor in any functions that it calls.
   	14. uninit_member: Non-static class member uvw_.envc is not initialized in this constructor nor in any functions that it calls.
   	16. uninit_member: Non-static class member uvw_.env is not initialized in this constructor nor in any functions that it calls.
   	18. uninit_member: Non-static class member uvw_.env_buf is not initialized in this constructor nor in any functions that it calls.
   	20. uninit_member: Non-static class member uvw_.env_buf_size is not initialized in this constructor nor in any functions that it calls.
   	
CID 276376 (#2 of 2): Uninitialized pointer field (UNINIT_CTOR)
22. uninit_member: Non-static class member uvw_.allocator is not initialized in this constructor nor in any functions that it calls.
 87      return;
 88
 89    env->isolate()->ThrowException(exception);

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/54333/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/54376/

[devsnek]

is this condition reachable when the isolate is terminated?

[mhdawson]

Since there is a return code from the function around which the CHECK as been added I believe it should be reachable.

[mhdawson]

Landed in c1a3a98