fix issue with instruction conversion

fixes #90
Merge pull request #106 from charsleysa/metadata

Fix issue with FloatCompare IR instruction conversion in X86
Bug fixes and workarounds

Bug fixes and workarounds, most notably a workaround for #107
Merge pull request #108 from charsleysa/metadata

Bug fixes and workarounds
- Bug fixes for Conditional Constant Propagation stage (incomplete)