RFR (XL) 8081519 Split globals.hpp to factor out the Flag class

[Gerard Ziemski]

Thank you Coleen for review.

> On Apr 6, 2018, at 3:51 PM, coleen.phillimore at oracle.com wrote:
> 
> 
> Gerard,
> 
> It looks like these files get the include jvmFlag.hpp transitively from globals_ext.hpp, but can you add an explicit #include "runtime/flags/jvmFlag.hpp" to the files that you've changed that don't explicitly include jvmFlagsConstraintList.hpp and others?  The include guards will prevent them from being included twice and it would be good if we ever change these to not include globals_ext.hpp.  eg:
> 
> http://cr.openjdk.java.net/~gziemski/8081519_rev2/src/hotspot/share/jvmci/jvmciCompilerToVM.cpp.udiff.html

Will do.


cheers