[Go] Object API support (#5339)

* start

* works for current usages!

* unpack: vector of struct

* optimize byte slice

* support nested struct

* support null table

* support struct

* support union

* update generated code

* grumble

* fix compiler warning

* update generated code

* wrap type in namespace

* bug

* wrap in namespace

* enum byte arrays

* generate struct for unions

* basic testing

* remove branching

* fix assert

* pack vector of fixed structs correctly

* omit null vectors

* Refactor Union Pack and UnPack methods

Remove append usage to increase code efficiency when dealing with large vectors

* generate goldens

tests/MyGame/Example/AnyAmbiguousAliases.go

@@ -2,7 +2,46 @@
 
 package Example
 
-import "strconv"
+import (
+	"strconv"
+
+	flatbuffers "github.com/google/flatbuffers/go"
+)
+
+type AnyAmbiguousAliasesT struct {
+	Type AnyAmbiguousAliases
+	Value interface{}
+}
+
+func AnyAmbiguousAliasesPack(builder *flatbuffers.Builder, t *AnyAmbiguousAliasesT) flatbuffers.UOffsetT {
+	if t == nil {
+		return 0
+	}
+	switch t.Type {
+	case AnyAmbiguousAliasesM1:
+		return MonsterPack(builder, t.Value.(*MonsterT))
+	case AnyAmbiguousAliasesM2:
+		return MonsterPack(builder, t.Value.(*MonsterT))
+	case AnyAmbiguousAliasesM3:
+		return MonsterPack(builder, t.Value.(*MonsterT))
+	}
+	return 0
+}
+
+func AnyAmbiguousAliasesUnPack(t AnyAmbiguousAliases, table flatbuffers.Table) *AnyAmbiguousAliasesT {
+	switch t {
+	case AnyAmbiguousAliasesM1:
+		x := Monster{_tab: table}
+		return &AnyAmbiguousAliasesT{ Type: AnyAmbiguousAliasesM1, Value: x.UnPack() }
+	case AnyAmbiguousAliasesM2:
+		x := Monster{_tab: table}
+		return &AnyAmbiguousAliasesT{ Type: AnyAmbiguousAliasesM2, Value: x.UnPack() }
+	case AnyAmbiguousAliasesM3:
+		x := Monster{_tab: table}
+		return &AnyAmbiguousAliasesT{ Type: AnyAmbiguousAliasesM3, Value: x.UnPack() }
+	}
+	return nil
+}
 
 type AnyAmbiguousAliases byte