[8u] RFR: 8246223: Windows build fails after JDK-8227269

[Alex Kashchenko]

Hi,

Please review the fix to JDK-8246223:

Bug: https://bugs.openjdk.java.net/browse/JDK-8246223

Webrev: https://cr.openjdk.java.net/~akasko/jdk8u/8246223/webrev.00/

Problem appeared to be caused by C99 syntax used in JDK-8227269 that is 
not supported by VS2010 compiler (newer VS versions were not affected).

This patch fixes the compatibility of classTrack.c with C89 moving 
variable declarations to the beginning of corresponding scope blocks.

Testing: checked that it can be compiled with VS2010 and newer toolchains.

-- 
-Alex