Unwind support for floats

Change-Id: I16e3dcfc551eade6f138f2adf571be86b1f8ab30
Handle invalid pop sequences

Change-Id: I2b88e51f52dff6e4a9f95fd058a8bce8de191504
review nits

Change-Id: I111a6541e4f435d80f57eac28e85ed156411ad73
More comment nits

Change-Id: I44fee9cdb3c88dc2145c8e83a01ae593fedfa738
Merge pull request #103 from awong-dev/float_unwind

Unwind support for floats