8248188: Add IntrinsicCandidate and API for Base64 decoding, add Power64LE intrinsic implementation.
This patch set encompasses the following commits:
Adds a new intrinsic candidate to the java.lang.Base64 class - decodeBlock(), and provides a flexible API for the intrinsic. The API is similar to the existing encodeBlock intrinsic.
Adds the code in HotSpot to check and martial the new intrinsic's arguments to the arch-specific intrinsic implementation.
Adds a Power64LE-specific implementation of the decodeBlock intrinsic.
Adds a JMH microbenchmark for both Base64 encoding and encoding.
Enhances the JTReg hotspot intrinsic "TestBase64.java" regression test to more fully test both decoding and encoding.
Reviewed-by: rriggs, mdoerr, kvn
