Update expandBodyForIteratorInline and setupSimultaneousIterators to take a ForLoop rather than a BlockStmt. Also provide a streamline entry to the expandBodyForIteratorInline recursion
Ensure that ForLoop generates a BlockStmt rather than a degenerate ForLoop
Localize use of the blockInfo object within expandForLoop
Merge pull request #879 from noakesmichael/iter-1

Continued effort to separate ForLoop from BlockStmt in LowerIterators

1) Propagate the ForLoop type, rather than BlockStmt, a little more deeply along a call chain.

2) Construct a BlockStmt object to replace what would be a degenerate ForLoop object

3) Reduce the direct use of the blockInfo CallExpr with expandForLoop


Compiled: STD clang/darwin, STD gcc/linux64, LLVM gcc/linux64
Tested: Full paratest --verify
Review: None