[ASTVerifier] Allow inout and Array to pointer conversion in variadic parameter positions

Fixes a verifier crash that prevented use of valid conversions.

Resolves: swiftlang#73454
Resolves: rdar://128109889

Author: xedin

lib/AST/ASTVerifier.cpp

@@ -1897,6 +1897,18 @@ class Verifier : public ASTWalker {
           continue;
         }
 
+        // If the argument is a concrete variadic expansion, let's check its
+        // every element.
+        if (auto *variadicExpansion = dyn_cast<VarargExpansionExpr>(subExpr)) {
+          if (auto *implicitArray =
+                  dyn_cast<ArrayExpr>(variadicExpansion->getSubExpr())) {
+            for (auto *element : implicitArray->getElements()) {
+              maybeRecordValidPointerConversionForArg(element);
+            }
+            return;
+          }
+        }
+
         break;
       }
 

validation-test/Sema/type_checker_crashers_fixed/issue-73454.swift

@@ -0,0 +1,21 @@
+// RUN: %target-typecheck-verify-swift
+
+// https://github.com/apple/swift/issues/73454
+
+func object_method_bind_ptrcall_v(
+  _: UnsafeMutableRawPointer?...
+) {
+}
+
+func setDensity(_ density: Double, ptr: UnsafeMutableRawPointer) {
+  var copy_density = density
+  var arr: [Int] = []
+
+  object_method_bind_ptrcall_v(&copy_density)
+  object_method_bind_ptrcall_v(&arr)
+
+  object_method_bind_ptrcall_v(&arr, &copy_density)
+
+  object_method_bind_ptrcall_v(ptr, &copy_density, &arr)
+  object_method_bind_ptrcall_v(&copy_density, ptr, &arr)
+}

validation-test/compiler_crashers_2/2ae771dc466f1acc.swift renamed to validation-test/compiler_crashers_2_fixed/2ae771dc466f1acc.swift

@@ -1,5 +1,5 @@
 // {"kind":"typecheck","original":"f0cca09d","signature":"swift::ASTWalker::PostWalkResult<swift::ArrayToPointerExpr*> (anonymous namespace)::Verifier::dispatchVisitPost<swift::ArrayToPointerExpr*>(swift::ArrayToPointerExpr*)"}
-// RUN: not --crash %target-swift-frontend -typecheck %s
+// RUN: %target-typecheck-verify-swift
 struct a {
   var b: String
 }