RFR(S): 8245021: Add method 'remove_if_existing' to growableArray.

[Patric Hedlin]

Dear all,

I would like to ask for help to review the following change/update:

Issue:  https://bugs.openjdk.java.net/browse/JDK-8245021
Webrev: http://cr.openjdk.java.net/~phedlin/tr8245021/


8245021: Add method 'remove_if_existing' to growableArray.

Minor improvement to simplify the code pattern "if contains then remove" 
found in a few places (in "compile.hpp").


Testing: hs-tier1-3


Best regards,
Patric