[SR-3896] Add missing r-value coercion for type(of:)'s argument

[CodaFi]

When this was migrated over to the awesome new special representation
of type(of:) the argument coercion didn’t come with it. The missing
load expression caused any l-value run through type(of:) to crash in the
verifier.

@jckarter, how does it look?

[CodaFi]

@swift-ci please smoke test

[jckarter]

Nice catch! Does withoutActuallyEscaping need the same thing?

[CodaFi]

Is there a way to take a non-escaping closure parameter as an l-value? The only permitted operation is a call.

[jckarter]

Do we check that before or after normal type-checking? We still don't want to crash if you write var g = f; withoutActuallyEscaping(g) { ... }