UPSTREAM: [Sema][Typo Correction] Fix another infinite loop on ambiguity

See also: D67515

- For the given call expression we would end up repeatedly
   trying to transform the same expression over and over again

- Fix is to keep the old TransformCache when checking for ambiguity

Differential Revision: https://reviews.llvm.org/D69060



Bug: 139945549
Bug: 145623332
(cherry picked from commit 7a2b704b)
Change-Id: Ie154eaf6363c8263f31329c1230fe398dcebd8f5
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>