[Nestmates] RFR: 8192889: [Nestmates] ciField constructor needs to clear nest-host related exceptions

[David Holmes]

Bug: https://bugs.openjdk.java.net/browse/JDK-8192889
webrev: https://bugs.openjdk.java.net/browse/JDK-8192889

Xcomp testing exposed another issue with the compiler thread.

In ciField::ciField(ciInstanceKlass* klass, int index) we have:

   // Access check based on declared_holder. canonical_holder should not 
be used
   // to check access because it can erroneously succeed. If this check 
fails,
   // propagate the declared holder to will_link() which in turn will 
bail out
   // compilation for this field access.
   if (!Reflection::verify_field_access(klass->get_Klass(), 
declared_holder->get_Klass(), canonical_holder, 
field_desc.access_flags(), true)) {
     _holder = declared_holder;
     _offset = -1;
     _is_constant = false;
    return;
   }

However if the access check failed because a nestmate access check 
encountered an exception, the pending exception will trigger an 
ExceptionMark entry failure in later processing. We need to clear the 
exception before returning.

Thanks,
David