SI-8451 quasiquotes now handle quirks of secondary constructors

Apparently even though the rhs of a secondary constructor looks like an expr,
it always gets wrapped in a block by the parser. This works just fine with
the typer, but crashes in uncurry. This commit brings quasiquotes in line with the parser.
Merge pull request #3659 from xeno-by/topic/uncurry-ctors

SI-8451 makes uncurry more forgiving