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.

This is done by declaring the temporary variable struct as 'static'.

The varinit test should rather be listed under compiler bugs.