This introduces tyStatic and successfully bootstraps and handles
few simple test cases. Static params within macros are no longer
treated as PNimrodNodes - they are now equivalent to constants
of the designated type.
It's unclear to me why for variables were treated as globals.
This is likely to cause many problems, but in this particular case
it was breaking the unittest/insepectArgs recursive function (the
for loop variable has a different value in each stack frame)
This postpones the semantic pass over the generic's body until
the generic is instantiated. There are several pros and cons for
this method and the capabilities that it enables may still be possible
in the old framework if we teach it a few new trick. Such an attempt
will follow in the next commits.
pros:
1) It allows macros to be expanded during generic instantiation that
will provide the body of the generic. See ``tmacrogenerics``.
2) The instantiation code is dramatically simplified. Dealing with unknown
types in the generic's body pre-pass requires a lot of hacky code and error
silencing in semTypeNode. See ``tgenericshardcases``.
cons:
1) There is a performance penalty of roughly 5% when bootstrapping.
2) Certain errors that used to be detected in the previous pre-pass won't
be detected with the new scheme until instantiation.
See the section `do notation` in the manual for more info.
* nkMacroStmt has been removed
Macro statements are now mapped to regular nkCall nodes.
The support for additional clauses (such as else, except, of, etc)
have been restored - they will now appear as additional arguments
for the nkCall node (as nkElse, nkExcept, etc nodes)
* fixed some regressions in the `is` operator and semCompiles
