When we run into a template parameter that should have a default
argument but doesn't (because previous template parameters had default
arguments), clear out all of the default arguments so that we maintain
the invariant that a template parameter has a default argument only if
subsequence template parameters also have default arguments.
Fixes a crash-on-invalid <rdar://problem/8913649>.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@124345 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed