RFR [XXS]: 8237382: Cleanup the OPT_SPEED_SRC file list in JvmFeatures.gmk

[Baesken, Matthias]

Hello, please review this very small change .

It removes file that are not present any more from the  OPT_SPEED_SRC file list in JvmFeatures.gmk  .

( this is a list of files to be optimized for speed when we otherwise optimize for size  in the minimal-JVM build)


Bug/webrev :

https://bugs.openjdk.java.net/browse/JDK-8237382

http://cr.openjdk.java.net/~mbaesken/webrevs/8237382.0/

Thanks, Matthias