RFR: 8200607: Add missing include dependency in bitMap.hpp

[Aleksey Shipilev]

On 04/03/2018 10:46 AM, Per Liden wrote:
> bitMap.hpp uses the MEMFLAGS type, but doesn't include allocation.hpp, where that type is defined.
> This problem was exposed when writing a small gtest test-case, which only included bitMap.hpp.
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8200607
> Webrev: http://cr.openjdk.java.net/~pliden/8200607/webrev.0

Looks good!

-Aleksey