Cast operations will still be evaluated at compile time in all cases
they did before because of the built-in constant propagation of the
IRBuilder, but when one of the parameters is not a constant it will
transparently be evaluated at runtime.
This avoids some errors in the partial evaluator. It is not yet complete
as all binops will need a similar treatment.
This interpreter currently complements the Go SSA level interpreter. It
may stay complementary or may be the only interpreter in the future.
This interpreter is experimental and not yet finished (there are known
bugs!) so it is disabled by default. It can be enabled by passing the
-initinterp flag.
The goal is to be able to run all initializations at compile time except
for the ones having side effects. This mostly works except perhaps for a
few edge cases.
In the future, this interpeter may be used to actually run regular Go
code, perhaps in a shell.
