[tailscale] runtime: add func TailscaleCurrentP

Updates #109

Signed-off-by: Brad Fitzpatrick <[email protected]>

Author: bradfitz

api/go1.52109.txt

@@ -0,0 +1 @@
+pkg runtime, func TailscaleCurrentP() int #109

src/runtime/tailscale_runtime.go

@@ -0,0 +1,8 @@
+package runtime
+
+// TailscaleCurrentP returns the runtime's currently executing 'p' ID.
+//
+// See https://github.com/tailscale/go/issues/109.
+func TailscaleCurrentP() int {
+	return int(getg().m.p.ptr().id)
+}