vendor: update github.com/hashicorp/hcl/v2 to v2.19.1

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

vendor/github.com/zclconf/go-cty/cty/function/stdlib/conversion.go

@@ -1,6 +1,7 @@
 package stdlib
 
 import (
+	"fmt"
 	"strconv"
 
 	"github.com/zclconf/go-cty/cty"
@@ -18,6 +19,7 @@ import (
 // a tuple.
 func MakeToFunc(wantTy cty.Type) function.Function {
 	return function.New(&function.Spec{
+		Description: fmt.Sprintf("Converts the given value to %s, or raises an error if that conversion is impossible.", wantTy.FriendlyName()),
 		Params: []function.Parameter{
 			{
 				Name: "v",
@@ -85,3 +87,36 @@ func MakeToFunc(wantTy cty.Type) function.Function {
 		},
 	})
 }
+
+// AssertNotNullFunc is a function which does nothing except return an error
+// if the argument given to it is null.
+//
+// This could be useful in some cases where the automatic refinment of
+// nullability isn't precise enough, because the result is guaranteed to not
+// be null and can therefore allow downstream comparisons to null to return
+// a known value even if the value is otherwise unknown.
+var AssertNotNullFunc = function.New(&function.Spec{
+	Description: "Returns the given value varbatim if it is non-null, or raises an error if it's null.",
+	Params: []function.Parameter{
+		{
+			Name: "v",
+			Type: cty.DynamicPseudoType,
+			// NOTE: We intentionally don't set AllowNull here, and so
+			// the function system will automatically reject a null argument
+			// for us before calling Impl.
+		},
+	},
+	Type: func(args []cty.Value) (cty.Type, error) {
+		return args[0].Type(), nil
+	},
+	RefineResult: refineNonNull,
+	Impl: func(args []cty.Value, retType cty.Type) (cty.Value, error) {
+		// Our argument doesn't set AllowNull: true, so we're guaranteed to
+		// have a non-null value in args[0].
+		return args[0], nil
+	},
+})
+
+func AssertNotNull(v cty.Value) (cty.Value, error) {
+	return AssertNotNullFunc.Call([]cty.Value{v})
+}