SILGenExpr crash when using parameter pack

[theblixguy]

class Thing<T> {
  var value: T
  init(_ value: T) { self.value = value }

  func combineThings<each U>(head: Thing<T>, tail: repeat Thing<each U>) {
    let _ = Thing<(T, repeat each U)>((head.value, repeat (each tail).value))
  }
}

This crashes on the latest nightly (Swift version 5.11-dev (LLVM 82306b901067e3c, Swift cabb5e109fa373f)) with:

SILGenExpr.cpp:6514: swift::Lowering::RValue swift::Lowering::SILGenFunction::emitRValue(swift::Expr *, swift::Lowering::SGFContext): Assertion `!E->getType()->hasLValueType() && "l-values must be emitted with emitLValue"' failed.

It does not crash on 5.9 though.