RFR (S): 8000313: C2 should use jlong for 64bit values

[Vladimir Ivanov]

http://cr.openjdk.java.net/~vlivanov/8000313/webrev.00/
25 lines changed: 0 ins; 0 del; 25 mod

This is a code cleanup. It replaces all occurrences of long with jlong
in C2 code to guarantee that 64-bit value is always used (it's not the
case for type long) and no overflow in subsequent arithmetic operations
occurs.

Testing: JPRT, full CTW on solaris_x64

Best regards,
Vladimir Ivanov