[CSApply] Make sure to load value before attempting implicit conversion

Author: xedin

lib/Sema/CSApply.cpp

@@ -6697,6 +6697,9 @@ Expr *ExprRewriter::coerceToType(Expr *expr, Type toType,
       auto *argExpr = locator.trySimplifyToExpr();
       assert(argExpr);
 
+      // Load the value for conversion.
+      argExpr = cs.coerceToRValue(argExpr);
+
       auto *implicitInit =
           CallExpr::createImplicit(ctx, TypeExpr::createImplicit(toType, ctx),
                                    /*args=*/{argExpr},

test/Misc/misc_diagnostics.swift

@@ -220,4 +220,12 @@ func test_implicit_cgfloat_conversion() {
 
     let c: Double = (a ?? 0) as CGFloat // Ok with implicit conversion
   }
+
+  func test_loading_tuple_elements(values: inout (CGFloat, CGFloat)) {
+    struct S {
+      init(x: Double, y: Double) {}
+      init(x: CGFloat, y: CGFloat) {}
+    }
+    _ = S(x: 0.0, y: values.0) // Ok
+  }
 }