doc/go1.2.txt: AllocsPerRun now quantized

R=golang-dev, khr, rsc
CC=golang-dev
https://golang.org/cl/9728045
diff --git a/doc/go1.2.txt b/doc/go1.2.txt
index fd09d6a..dcb4783 100644
--- a/doc/go1.2.txt
+++ b/doc/go1.2.txt
@@ -12,3 +12,4 @@
 
 fmt: indexed access to arguments in Printf etc. (CL 9680043).
 io: Copy prioritizes WriterTo over ReaderFrom (CL 9462044).
+testing: AllocsPerRun is now quantized to an integer (the type is still float64) (CL 9837049).