swift234

When parsing if/while statements, if the condition turns out to be a
closure, reparse it as a brace statement instead of attempting to
repurpose the closure body. Suppress diagnostics from the initial
condition parse until we're committed to that parse.

<rdar://problem/18940198> Fuzzing Swift: performTypeChecking(...) crashes in ContextualizeClosures::walkToExprPre(...): Assertion failed: "Incorrect parent decl context for closure"

Swift SVN r25438