RFR (also tedious) 8216167: Update include guards to reflect correct directories

[coleen.phillimore at oracle.com]

Summary: Use script and some manual fixup to fix directores names in 
include guards.

Makes include guards match the current directory rooted at src/hotspot 
(removes VM_ in most cases).

This should be low risk.  Tested with mach5 tier1 and tier2.

https://bugs.openjdk.java.net/browse/JDK-8216167
http://cr.openjdk.java.net/~coleenp/8216167.01.diff

I didn't generate a webrev as a space concern for cr.openjdk.java.net 
and nobody should click on it.  Script is posted in bug.  Will update 
and check copyright headers with hg commit.

Thanks,
Coleen