Use the coding tables from fidlgen_hlcpp

The coding tables have been produced by fidlgen_hlcpp instead of fidlc
since I21cc21085d826b61b589b53f64c272dd298bebbe.

Bug: b/42115242
Change-Id: I89140d0bb75e4a5ad510213485f3ca76121a1f2c
Reviewed-on: https://fuchsia-review.googlesource.com/c/fidlbolt/+/978237
Reviewed-by: Ian McKellar <ianloic@google.com>
diff --git a/backend/server.go b/backend/server.go
index 5c209c0..beb3f7f 100644
--- a/backend/server.go
+++ b/backend/server.go
@@ -423,13 +423,6 @@
 	}
 
 	switch r.OutputMode {
-	case HLCPP:
-		if r.Options.File == "tables" {
-			return fidlc("--tables", "/dev/stdout")
-		}
-	}
-
-	switch r.OutputMode {
 	case FIDL:
 		prog := s.fidlFormat
 		if r.Options.Lint {
@@ -519,6 +512,8 @@
 			return temp.readFile(libraryDirs, "cpp", "fidl.cc")
 		case "test":
 			return temp.readFile(libraryDirs, "cpp", "fidl_test_base.h")
+		case "tables":
+			return temp.readFile(libraryDirs, "cpp", "tables.c")
 		default:
 			return "", fmt.Errorf("invalid file: %q", r.Options.File)
 		}