RFR(S): 8164738: Convert AltHashing_test to GTest

[Kirill Zhaldybin]

Dear all,

Could you please review this fix for 8164738?

To convert the test I added new friend class to AltHashing class so we 
could access private member function static juint murmur3_32(const int* 
data, int len). There are also few formating fixes.

WebRev: http://cr.openjdk.java.net/~kzhaldyb/webrevs/JDK-8164738/webrev.00/
CR: https://bugs.openjdk.java.net/browse/JDK-8164738

Regards, Kirill