[fidl][go] Support unknown data for tables (1/4)

This ignores the I_unknownData field for tables before
they are emitted by fidlgen.

Step 1: Ib6f9dce7cea743ce50f61fc5cba8b5e6c4c49242
Step 2: I3e839ceb761820299238f19c3bebdcd95fd1eb2f
Step 3: Ifd7ebe3db2544f4a07add78600d008a072c1d1a2
Step 4: I51a58157c498761b4b85bf4309bb61461cc39a91

Test: fx test -v go-fidl-tests
Change-Id: Ib6f9dce7cea743ce50f61fc5cba8b5e6c4c49242
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/go/+/438334
Reviewed-by: Pascal Perez <pascallouis@google.com>
Reviewed-by: Mitchell Kember <mkember@google.com>
Commit-Queue: Pascal Perez <pascallouis@google.com>
diff --git a/src/syscall/zx/fidl/encoding_new.go b/src/syscall/zx/fidl/encoding_new.go
index 4af0a56..c7f9c6f 100644
--- a/src/syscall/zx/fidl/encoding_new.go
+++ b/src/syscall/zx/fidl/encoding_new.go
@@ -319,7 +319,7 @@
 			continue
 		}
 
-		if kind == xunionTag && isUnknownDataField(field.Name) {
+		if (kind == xunionTag || kind == tableTag) && isUnknownDataField(field.Name) {
 			continue
 		}