RFR: JDK-8035870 - Check jdk/src/windows/native/java/io/WinNTFileSystem_md.c for JNI pending exceptions

[Mark Sheppard]

Hi
    please oblige and review the following changes
http://cr.openjdk.java.net/~msheppar/8035870/webrev/

which address the issues raised in
https://bugs.openjdk.java.net/browse/JDK-8035870

summary:
checks to return values from malloc added with appropriate 
JNU_ThrowOutOfMemoryError added

regards
Mark