Fixes#63
Fix is simple: all labels refered by the br_table instruction must have same value type (or NoResult in case if they don't have result). So we just take the default label and check other labels against it.
These limits seems to be picked arbitrary, and I just made it arbitrary larger.
We need to reconsider these limits, ideally providing to user a way to customize the limits.
FWIW, When the last time I've tried to run gcc's torture testsuite with wasmi it also bumped into this limit.
Fixes#41.
* Initial implementation
* Not use grow as it is makes debug builds very slow
* Use Pages::BYTE_SIZE for LINEAR_MEMORY_PAGE_SIZE
* Tidy docs.
* Use memory_units from git.