fix: avoid circular references to list/map/object attributes (#575)

This brings in hashicorp/hcl-lang#64

Fixes #573

go.mod

@@ -12,7 +12,7 @@ require (
 	github.com/hashicorp/go-memdb v1.3.2
 	github.com/hashicorp/go-multierror v1.1.1
 	github.com/hashicorp/go-version v1.3.0
-	github.com/hashicorp/hcl-lang v0.0.0-20210625140347-b5b9a34fd1c6
+	github.com/hashicorp/hcl-lang v0.0.0-20210702130035-edd4fd2759e8
 	github.com/hashicorp/hcl/v2 v2.10.0
 	github.com/hashicorp/terraform-exec v0.14.0
 	github.com/hashicorp/terraform-json v0.12.0

go.sum

@@ -191,8 +191,8 @@ github.com/hashicorp/golang-lru v0.5.4/go.mod h1:iADmTwqILo4mZ8BN3D2Q6+9jd8WM5uG
 github.com/hashicorp/hcl v1.0.0 h1:0Anlzjpi4vEasTeNFn2mLJgTSwt0+6sfsiTG8qcWGx4=
 github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T20WEQ=
 github.com/hashicorp/hcl-lang v0.0.0-20210616121206-bd34ebcc883b/go.mod h1:uMsq6wV8ZXEH8qndov4tncXlHDYnZ8aHsGmS4T74e2o=
-github.com/hashicorp/hcl-lang v0.0.0-20210625140347-b5b9a34fd1c6 h1:vhjdOf16VR3QOrLOR9Il8Vjyswr6RkT6G5UuvZyWDLQ=
-github.com/hashicorp/hcl-lang v0.0.0-20210625140347-b5b9a34fd1c6/go.mod h1:rDEzcPJU1AYRanWbpH9AZEik9i+jv1aoKkwqjfs7NyA=
+github.com/hashicorp/hcl-lang v0.0.0-20210702130035-edd4fd2759e8 h1:8bZ7+R5eN08bKiBCxC6iKD2C/drbaCkVvnmlQ62avNI=
+github.com/hashicorp/hcl-lang v0.0.0-20210702130035-edd4fd2759e8/go.mod h1:rDEzcPJU1AYRanWbpH9AZEik9i+jv1aoKkwqjfs7NyA=
 github.com/hashicorp/hcl/v2 v2.10.0 h1:1S1UnuhDGlv3gRFV4+0EdwB+znNP5HmcGbIqwnSCByg=
 github.com/hashicorp/hcl/v2 v2.10.0/go.mod h1:FwWsfWEjyV/CMj8s/gqAuiviY72rJ1/oayI9WftqcKg=
 github.com/hashicorp/logutils v1.0.0/go.mod h1:QIAnNjmIWmVIIkWDTG1z5v++HQmx9WQRO+LraFDTW64=