[llvm] [LangRef] asm clobber constrains: '~memory' allows reads and synchronization (PR #150191)

[Eli Friedman via llvm-commits]

efriedma-quic wrote:

CC @bwendling ; he's been looking at inline asm stuff recently.

If nobody else looks, I can try to find some time to look at the SelectionDAG code... poke me in a couple weeks.

https://github.com/llvm/llvm-project/pull/150191