This tests rejection and warnings about bad applications of type operators.

It now filters out the remaining lines that are issued by make. Also
print diagnistics only once per failed test program.

The new implementation gives much better diagnistics in case something
goes wrong, including the whole compiler (snc) output. It is also
simpler and uses Test::More in a more idiomatic way.

This tests that a global SNL variable is (correctly) shadowed by a
function parameter with the same name, even in re-entrant mode.

This compiler test adds a lot of complicated declarations and type
expressions.

This tests that for, while, if, and if/else statements
can be nested to at least depth 40.

Thanks to Mark Rivers who suggested this test.

Implementing this meant that the invariants governing the
three-state values (none, single, multi) of the assign,
monitor, sync, and syncq members had to be redesigned.
More comments in analysis.c indicate where these laws are
established and where we depend on them (assert them).
Also added / changed corresponding tests in test/compiler.