RSC Compile performance is 12.5% faster under 2.11 vs 2.12

[rorygraves]

When running RSC with 2.12.4 vs 2.11.12 (i.e. RSC itself is compiled with 2.12 - I observe a 12.5% performance drop

The code is very vanilla - and whlist this is not directly 'compiler' related it is worth investigating and it might flag something interesting.

In RSC build.sbt
Change:
scalaVersion := versions.scala211, to scalaVersion := versions.scala212,

In Sbt:

 rscJVM/clean
benchRscJVM/clean
benchRscJVM/jmh:run HotRscTypecheck

2.11
[info] # Warmup Iteration   9: 24.509 ±(99.9%) 0.191 ms/op
[info] # Warmup Iteration  10: 24.555 ±(99.9%) 0.201 ms/op
2.12
[info] # Warmup Iteration   8: 27.486 ±(99.9%) 0.292 ms/op
[info] # Warmup Iteration   9: 27.423 ±(99.9%) 0.451 ms/op