RFR: Remove old code from escape analysis

[Roman Kennke]

This seems to be an unused block of code in escape analysis. Inspecting
the code it appears to be a leftover from when we emitted RBs as
LoadP+AddP, iow when it was treated like a normal field load. I placed a
ShouldNotReachHere() in the block and it did not blow up when running
tier3_gc_shenandoah. Let's remove it. Ok?

Tests: tier3_gc_shenandoah

http://cr.openjdk.java.net/~rkennke/escape-remove-old-code/webrev.00/

Ok?

Roman