RFR 8248043: Need to eliminate excessive i2l conversions

[Boris Ulasevich]

Hi all,

Please review the change to eliminate the unnecessary i2l conversion
for expressions like this: "if (intValue == 1L)".

http://bugs.openjdk.java.net/browse/JDK-8248043
http://cr.openjdk.java.net/~bulasevich/8248043/webrev.01

The provided benchmark shows performance boost on all platforms:
- Intel Xeon: 32.705 --> 14.234 ns/op
- arm64: 42.060 --> 25.456 ns/op
- arm32: 618.763 --> 314.040 ns/op
- ppc8:  81.218 --> 63.026 ns/op

Testing done: jtreg, jck.

thanks,
Boris