Upgrade hcl to v2

Signed-off-by: Patrick Van Stee <patrick@vanstee.me>

vendor/github.com/zclconf/go-cty/cty/function/error.go

@@ -0,0 +1,50 @@
+package function
+
+import (
+	"fmt"
+	"runtime/debug"
+)
+
+// ArgError represents an error with one of the arguments in a call. The
+// attribute Index represents the zero-based index of the argument in question.
+//
+// Its error *may* be a cty.PathError, in which case the error actually
+// pertains to a nested value within the data structure passed as the argument.
+type ArgError struct {
+	error
+	Index int
+}
+
+func NewArgErrorf(i int, f string, args ...interface{}) error {
+	return ArgError{
+		error: fmt.Errorf(f, args...),
+		Index: i,
+	}
+}
+
+func NewArgError(i int, err error) error {
+	return ArgError{
+		error: err,
+		Index: i,
+	}
+}
+
+// PanicError indicates that a panic occurred while executing either a
+// function's type or implementation function. This is captured and wrapped
+// into a normal error so that callers (expected to be language runtimes)
+// are freed from having to deal with panics in buggy functions.
+type PanicError struct {
+	Value interface{}
+	Stack []byte
+}
+
+func errorForPanic(val interface{}) error {
+	return PanicError{
+		Value: val,
+		Stack: debug.Stack(),
+	}
+}
+
+func (e PanicError) Error() string {
+	return fmt.Sprintf("panic in function implementation: %s\n%s", e.Value, e.Stack)
+}