docs: float->float64 plus a couple of other tweaks.

R=rsc, gri
CC=golang-dev
https://golang.org/cl/3978042
diff --git a/doc/gccgo_install.html b/doc/gccgo_install.html
index 393e579..2ab6dcd 100644
--- a/doc/gccgo_install.html
+++ b/doc/gccgo_install.html
@@ -296,8 +296,8 @@
 functions have equivalent types:
 
 <pre>
-func GoFunction(int) (int, float)
-struct { int i; float f; } CFunction(int)
+func GoFunction(int) (int, float64)
+struct { int i; float64 f; } CFunction(int)
 </pre>
 
 <p>