[clang] [clang] Convert second arg of __builtin_assume_aligned to ConstantExpr (PR #161314)

[Erich Keane via cfe-commits]

erichkeane wrote:

@Fznamznon : Your patch 9ad72df55cb74 seems at least closely related here: in CGExprScalar.cpp in VisitConstantExpr.

This patch is unfortunately  just revealing a bug there, where the type of the constant expression is a L value constant but isn't getting the 'pointer' type for the `EmitLoadOfScalar`.

It isn't clear to me what SHOULD happen, but that at least seems wrong.

https://github.com/llvm/llvm-project/pull/161314