Introduce an invalid context for each statement

  Collect the error domain contexts (formerly in the ErrorDomainCtxMap)
  for each statement in the new InvalidContext member variable. While
  this commit is basically a [NFC] it is a first step to make hoisting
  sound by allowing a more fine grained record of invalid contexts,
  e.g., here on statement level.

llvm-svn: 266053
GitOrigin-RevId: 7c01357cef0c0809d079e96d52609b5ed8ae6192