Revert [Sema] Resolve placeholder types before type deduction to silence...

Revert [Sema] Resolve placeholder types before type deduction to silence spurious `-Warc-repeated-use-of-weak` warnings

This reverts r365382 (git commit 8b1becf2)

Appears to regress this semi-reduced fragment of valid code from windows
SDK headers:

  #define InterlockedIncrement64 _InterlockedIncrement64
  extern "C" __int64 InterlockedIncrement64(__int64 volatile *Addend);
  #pragma intrinsic(_InterlockedIncrement64)
  unsigned __int64 InterlockedIncrement(unsigned __int64 volatile *Addend) {
    return (unsigned __int64)(InterlockedIncrement64)((volatile __int64 *)Addend);
  }

Found on a buildbot here, but no mail was sent due to it already being
red:
http://lab.llvm.org:8011/builders/sanitizer-windows/builds/48067

llvm-svn: 365393