Propagate whether an id-expression is the immediate argument of

an '&' expression from the second caller of ActOnIdExpression.

Teach template argument deduction that an overloaded id-expression
doesn't give a valid type for deduction purposes to a non-static
member function unless the expression has the correct syntactic
form.

Teach ActOnIdExpression that it shouldn't try to create implicit
member expressions for '&function', because this isn't a        
permitted form of use for member functions.

Teach CheckAddressOfOperand to diagnose these more carefully.
Some of these cases aren't reachable right now because earlier
diagnostics interrupt them.

llvm-svn: 112258