Fixing initialization issue for IOCP handle.

[CIPop]

Contributes to #20096.

Testing was manually performed.
The change was minimized to simplify a 2.0 port.

[stephentoub]

@mmitche, can you tell what the problem is with the Portable Windows x64 Debug Build leg? It seems like all tests have passed.
https://ci3.dot.net/job/dotnet_corefx/job/master/job/portable-windows-Config_Debug+OuterLoop_false_prtest/92/

[CIPop]

the Portable Windows x64 Debug Build leg

Console shows an RPC issue:

12:58:06  > git fetch --tags --progress https://github.com/dotnet/corefx.git +refs/pull/*:refs/remotes/origin/pr/* # timeout=30
12:58:07 ERROR: Error fetching remote repo 'origin'
12:58:07 hudson.plugins.git.GitException: Failed to fetch from https://github.com/dotnet/corefx.git
12:58:07 	at hudson.plugins.git.GitSCM.fetchFrom(GitSCM.java:809)
12:58:07 	at hudson.plugins.git.GitSCM.retrieveChanges(GitSCM.java:1076)
12:58:07 	at hudson.plugins.git.GitSCM.checkout(GitSCM.java:1107)
12:58:07 	at org.jenkinsci.plugins.workflow.steps.scm.SCMStep.checkout(SCMStep.java:109)
12:58:07 	at org.jenkinsci.plugins.workflow.steps.scm.SCMStep$StepExecutionImpl.run(SCMStep.java:83)
12:58:07 	at org.jenkinsci.plugins.workflow.steps.scm.SCMStep$StepExecutionImpl.run(SCMStep.java:73)
12:58:07 	at org.jenkinsci.plugins.workflow.steps.AbstractSynchronousNonBlockingStepExecution$1$1.call(AbstractSynchronousNonBlockingStepExecution.java:47)
12:58:07 	at hudson.security.ACL.impersonate(ACL.java:260)
12:58:07 	at org.jenkinsci.plugins.workflow.steps.AbstractSynchronousNonBlockingStepExecution$1.run(AbstractSynchronousNonBlockingStepExecution.java:44)
12:58:07 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
12:58:07 	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
12:58:07 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
12:58:07 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
12:58:07 	at java.lang.Thread.run(Thread.java:745)
12:58:07 Caused by: hudson.plugins.git.GitException: Command "git fetch --tags --progress https://github.com/dotnet/corefx.git +refs/pull/*:refs/remotes/origin/pr/*" returned status code 128:
12:58:07 stdout: 
12:58:07 stderr: fatal: The remote end hung up unexpectedly
12:58:07 error: RPC failed; curl 18 transfer closed with outstanding read data remaining
12:58:07 
12:58:07 	at org.jenkinsci.plugins.gitclient.CliGitAPIImpl.launchCommandIn(CliGitAPIImpl.java:1877)
12:58:07 	at org.jenkinsci.plugins.gitclient.CliGitAPIImpl.launchCommandWithCredentials(CliGitAPIImpl.java:1596)
12:58:07 	at org.jenkinsci.plugins.gitclient.CliGitAPIImpl.access$300(CliGitAPIImpl.java:71)
12:58:07 	at org.jenkinsci.plugins.gitclient.CliGitAPIImpl$1.execute(CliGitAPIImpl.java:348)
12:58:07 	at org.jenkinsci.plugins.gitclient.RemoteGitImpl$CommandInvocationHandler$1.call(RemoteGitImpl.java:153)
12:58:07 	at org.jenkinsci.plugins.gitclient.RemoteGitImpl$CommandInvocationHandler$1.call(RemoteGitImpl.java:146)
12:58:07 	at hudson.remoting.UserRequest.perform(UserRequest.java:153)
12:58:07 	at hudson.remoting.UserRequest.perform(UserRequest.java:50)
12:58:07 	at hudson.remoting.Request$2.run(Request.java:336)
12:58:07 	at hudson.remoting.InterceptingExecutorService$1.call(InterceptingExecutorService.java:68)
12:58:07 	at java.util.concurrent.FutureTask.run(Unknown Source)
12:58:07 	at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
12:58:07 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
12:58:07 	at hudson.remoting.Engine$1$1.run(Engine.java:94)
12:58:07 	at java.lang.Thread.run(Unknown Source)
12:58:07 	at ......remote call to JNLP4-connect connection from 52.183.118.25/52.183.118.25:49174(Native Method)
12:58:07 	at hudson.remoting.Channel.attachCallSiteStackTrace(Channel.java:1545)
12:58:07 	at hudson.remoting.UserResponse.retrieve(UserRequest.java:253)
12:58:07 	at hudson.remoting.Channel.call(Channel.java:830)
12:58:07 	at org.jenkinsci.plugins.gitclient.RemoteGitImpl$CommandInvocationHandler.execute(RemoteGitImpl.java:146)
12:58:07 	at sun.reflect.GeneratedMethodAccessor520.invoke(Unknown Source)
12:58:07 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
12:58:07 	at java.lang.reflect.Method.invoke(Method.java:498)
12:58:07 	at org.jenkinsci.plugins.gitclient.RemoteGitImpl$CommandInvocationHandler.invoke(RemoteGitImpl.java:132)
12:58:07 	at com.sun.proxy.$Proxy168.execute(Unknown Source)
12:58:07 	at hudson.plugins.git.GitSCM.fetchFrom(GitSCM.java:807)
12:58:07 	... 13 more