typoe in Level 1 commit (BCodeType's TypeFlowInterpreter)
typo in LCC commit
new optimizer: GC-savvy closures
sharing immutable Trees for lower GC overhead
factory for scala.runtime.*Ref thus fixing root cause of SI-6863

This commit does away with an error-prone division of labor between UnCurry and LambdaLift, a division of labor by which UnCurry had to anticipate under which circumstances LambdaLift creates a scala.runtime.*Ref whose initial value is given by a an expression including a Try in non-statement position. That sounds complicated, and it is.

The solution so far (fixing SI-6863) is replaced by a simpler approach, at the cost of forward binary comptability with pre-2.11 releases, this time fixing the root cause of SI-6863.

From now on, a s.r.*Ref is instantiated via invocation of a static factory method in the s.r.*Ref class in question. Unlike the code that was emitted so far (which involved NEW refclass, DUP, expr, INVOKESPECIAL refclass.<init>) the "expr" doesn't appear on the operand stack on top of the *Ref value being initialized. In other words, the *Ref initialization is in statement position provided "expr" is.
another correction to LCC commit
tracking static-modules and custom-value-classes
module loads deliver non-null, NullnessPropagator
module loads deliver non-null, TypeFlowInterpreter
prune unneeded arguments to static-HiO resulting from closure-inlining