Upgrade hcl to v2

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

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

@@ -0,0 +1,70 @@
+package function
+
+import (
+	"github.com/zclconf/go-cty/cty"
+)
+
+// Parameter represents a parameter to a function.
+type Parameter struct {
+	// Name is an optional name for the argument. This package ignores this
+	// value, but callers may use it for documentation, etc.
+	Name string
+
+	// A type that any argument for this parameter must conform to.
+	// cty.DynamicPseudoType can be used, either at top-level or nested
+	// in a parameterized type, to indicate that any type should be
+	// permitted, to allow the definition of type-generic functions.
+	Type cty.Type
+
+	// If AllowNull is set then null values may be passed into this
+	// argument's slot in both the type-check function and the implementation
+	// function. If not set, such values are rejected by the built-in
+	// checking rules.
+	AllowNull bool
+
+	// If AllowUnknown is set then unknown values may be passed into this
+	// argument's slot in the implementation function. If not set, any
+	// unknown values will cause the function to immediately return
+	// an unkonwn value without calling the implementation function, thus
+	// freeing the function implementer from dealing with this case.
+	AllowUnknown bool
+
+	// If AllowDynamicType is set then DynamicVal may be passed into this
+	// argument's slot in the implementation function. If not set, any
+	// dynamic values will cause the function to immediately return
+	// DynamicVal value without calling the implementation function, thus
+	// freeing the function implementer from dealing with this case.
+	//
+	// Note that DynamicVal is also unknown, so in order to receive dynamic
+	// *values* it is also necessary to set AllowUnknown.
+	//
+	// However, it is valid to set AllowDynamicType without AllowUnknown, in
+	// which case a dynamic value may be passed to the type checking function
+	// but will not make it to the *implementation* function. Instead, an
+	// unknown value of the type returned by the type-check function will be
+	// returned. This is suggested for functions that have a static return
+	// type since it allows the return value to be typed even if the input
+	// values are not, thus improving the type-check accuracy of derived
+	// values.
+	AllowDynamicType bool
+
+	// If AllowMarked is set then marked values may be passed into this
+	// argument's slot in the implementation function. If not set, any
+	// marked value will be unmarked before calling and then the markings
+	// from that value will be applied automatically to the function result,
+	// ensuring that the marks get propagated in a simplistic way even if
+	// a function is unable to handle them.
+	//
+	// For any argument whose parameter has AllowMarked set, it's the
+	// function implementation's responsibility to Unmark the given value
+	// and propagate the marks appropriatedly to the result in order to
+	// avoid losing the marks. Application-specific functions might use
+	// special rules to selectively propagate particular marks.
+	//
+	// The automatic unmarking of values applies only to the main
+	// implementation function. In an application that uses marked values,
+	// the Type implementation for a function must always be prepared to accept
+	// marked values, which is easy to achieve by consulting only the type
+	// and ignoring the value itself.
+	AllowMarked bool
+}