[Proposal] Relax diagnostics for pointer arguments to C functions
[Proposal] Relax diagnostics for pointer arguments to C functions

Apply C language rules to the existing implicit UnsafePointer
conversions on function arguments when the callee is a C function
decl.

apple/swift-evolution,apple/swift-evolution,natecook1000/swift-evolution,abertelrud/swift-evolution,natecook1000/swift-evolution,abertelrud/swift-evolution