RFR 8248006 : Revisit exceptions thrown when creating an HttpClient fails due to unavailability of underlying resources.

[Rahul Yadav]

Hello,

Request to have my fix reviewed for issue:

JDK-8248006:  Revisit exceptions thrown when creating an HttpClient 
fails due to unavailability of underlying resources.

This fix updates jdk.internal.net.http.HttpClientImpl to throw an 
UncheckedIOException instead of InternalError,
when creating the HttpClient fails due to underlying resources being not 
available, when Selector.open(), which is
called from the underlying HttpClient implementation constructor, throws 
an IOException.


Issue:  https://bugs.openjdk.java.net/browse/JDK-8248006
webrev: http://cr.openjdk.java.net/~ryadav/webrev_8248006/index.html
csr :   https://bugs.openjdk.java.net/browse/JDK-8251198

- rahul