all: invert use_golang_protobuf_v1 tag

Invert the build tag such that the default is to use the reimplementation
that uses v2 under the hood.

Change-Id: I04ee912ddd59b387c2fbf0146b779dd99b060e93
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/169297
Reviewed-by: Herbie Ong <herbie@google.com>
diff --git a/proto/hooks_disabled.go b/proto/hooks_disabled.go
index fe9aaa0..b604f81 100644
--- a/proto/hooks_disabled.go
+++ b/proto/hooks_disabled.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !proto_reimpl
+// +build use_golang_protobuf_v1
 
 package proto
 
diff --git a/proto/hooks_enabled.go b/proto/hooks_enabled.go
index c117ba4..1c6e97f 100644
--- a/proto/hooks_enabled.go
+++ b/proto/hooks_enabled.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build proto_reimpl
+// +build !use_golang_protobuf_v1
 
 package proto
 
diff --git a/proto/properties.go b/proto/properties.go
index 5c4d44d..6f15aeb 100644
--- a/proto/properties.go
+++ b/proto/properties.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !proto_reimpl
+// +build use_golang_protobuf_v1
 
 package proto
 
diff --git a/proto/properties_alt.go b/proto/properties_alt.go
index 8fba1c4..56b8a66 100644
--- a/proto/properties_alt.go
+++ b/proto/properties_alt.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build proto_reimpl
+// +build !use_golang_protobuf_v1
 
 package proto
 
diff --git a/test.bash b/test.bash
index 11af78d..a7351bf 100755
--- a/test.bash
+++ b/test.bash
@@ -11,7 +11,7 @@
 RESET="\x1b[0m"
 
 echo -e "${BOLD}go test${RESET}"
-RET_TEST=$((go test ./... && go test -tags proto_reimpl ./...) | egrep -v "^(ok|[?])\s+")
+RET_TEST=$((go test ./... && go test -tags use_golang_protobuf_v1 ./...) | egrep -v "^(ok|[?])\s+")
 if [[ ! -z "$RET_TEST" ]]; then echo "$RET_TEST"; echo; fi
 
 echo -e "${BOLD}go generate${RESET}"