review(XXS): 7046893: LP64 problem with double_quadword in c1_LIRAssembler_x86.cpp

[Igor Veresov]

We had invalid casts in address computation. The pointer was cast to 
long, which on Windows is 32bit, so the upper bits were lost.

Webrev: http://cr.openjdk.java.net/~iveresov/7046893/webrev.00/

Contributed by: Thomas.Salter at unisys.com