Migrate users of breakLabelGet and continueLabelGet to be LoopStmt rather than BlockStmt
Migrate the loop label API from BlockStmt to LoopStmt
Merge pull request #998 from noakesmichael/label-0

Migrate labels from BlockStmt to LoopStmt

1) Update a few locations that were reading the break/continue label through a BlockStmt*

2) Move the instance variables and methods.

Compiled: STD clang/darwin, STD gcc/linux64, LLVM gcc/linux
Tested: paratest --verify; ignored the BLOCK_UNLOCAL regression
Review: none