Pull in r323998 from upstream clang trunk (by Richard Smith):
PR36157: When injecting an implicit function declaration in C89, find the right DeclContext rather than injecting it wherever we happen to be. This avoids creating functions whose DeclContext is a struct or similar.
This fixes assertion failures when parsing certain not-completely-valid
struct declarations.
Reported by: ae
PR: 225862
MFC after: 3 months
X-MFC-With: r327952