- this avoids using relative include paths which are forbidden by the style guide
- makes the code more readable since it's clear which header is meant
- allows for starting to use checkdeps

BUG=none
R=jkummerow@chromium.org, danno@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/304153016

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21625 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

- Move HType to it's own file.
- Add HType::HeapObject and some other useful types.
- Get rid of the broken and useless HType::NonPrimitive.
- Introduce HType::FromType() to convert from HeapType to HType.
- Also add unit tests for HType.
- Fix types in Crankshaft.

R=rossberg@chromium.org

Review URL: https://codereview.chromium.org/300893003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21578 ce2b1a6d-e550-0410-aec6-3dcde31c8c00