inlining depth effects on indexOf

[franz1981]

#10737 has introduced a smarter way to search for a byte into an array stream, but similarly to other methods on ByteBuf it can still get some megamorphic behaviour (due to the ByteBuf hierarchy) or can just fail to inline whatever PlatformDependent method used to access the underline memory, due to call stack depth.

#10368 has improved such behaviour that depends on the inlining strategy used by the OpenJDK (maybe Graal or OpenJ9 behave differently) at the cost of duplicating some code: I'm leaving this issue here if anyone is interested to investigate the impact when indexOf is used in the Netty codebase itself (for Stomp?) ie in a more controlled env.