EscapeUtils: consider that a pointer argument can escape a function call

Unlike addresses of indirect arguments, a pointer argument (e.g. `UnsafePointer`) can escape a function call.
For example, it can be returned.

Fixes a miscompile
rdar://154124497

SwiftCompilerSources/Sources/Optimizer/Utilities/EscapeUtils.swift

@@ -640,7 +640,7 @@ fileprivate struct EscapeWalker<V: EscapeVisitor> : ValueDefUseWalker,
     }
 
     // Indirect arguments cannot escape the function, but loaded values from such can.
-    if !followLoads(at: path) {
+    if argOp.value.type.isAddress && !followLoads(at: path) {
       if let beginApply = apply as? BeginApplyInst {
         // begin_apply can yield an address value.
         if !indirectResultEscapes(of: beginApply, path: path) {