Emit an update record if we instantiate the definition of a function template
specialization from a module. (This can also happen for function template
specializations in PCHs if they're instantiated eagerly, because they're
constexpr or have a deduced return type.)


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@204547 91177308-0d34-0410-b5e6-96231b3b80d8