sort, internal/reflectlite: flesh out reflectlite enough for use by sort

Now the net package is back to no longer depending on unicode. And lock that in
with a test.

Fixes #30440

Change-Id: I18b89b02f7d96488783adc07308da990f505affd
Reviewed-on: https://go-review.googlesource.com/c/go/+/169137
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

1 files changed, 12 insertions, 0 deletions

diff --git a/src/runtime/map.go b/src/runtime/map.go
index 0ebbf2ae76..bb32526846 100644
--- a/src/runtime/map.go
+++ b/src/runtime/map.go
@@ -1371,6 +1371,18 @@ func reflect_maplen(h *hmap) int {
 	return h.count
 }
 
+//go:linkname reflectlite_maplen internal/reflectlite.maplen
+func reflectlite_maplen(h *hmap) int {
+	if h == nil {
+		return 0
+	}
+	if raceenabled {
+		callerpc := getcallerpc()
+		racereadpc(unsafe.Pointer(h), callerpc, funcPC(reflect_maplen))
+	}
+	return h.count
+}
+
 //go:linkname reflect_ismapkey reflect.ismapkey
 func reflect_ismapkey(t *_type) bool {
 	return ismapkey(t)