test: s/float/float32/

I just committed a patch to gccgo that notices that float was
never defined, causing an additional unmatched error message.
Rename the type to avoid that message.

R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/6947049

test/fixedbugs/bug085.go

@@ -20,7 +20,7 @@ Bus error
 
 /* expected scope hierarchy (outermost to innermost)
 
-universe scope (contains predeclared identifiers int, float, int32, len, etc.)
+universe scope (contains predeclared identifiers int, float32, int32, len, etc.)
 "solar" scope (just holds the package name P so it can be found but doesn't conflict)
 global scope (the package global scope)
 local scopes (function scopes)

test/fixedbugs/bug228.go

@@ -8,11 +8,11 @@ package main
 
 func f(x int, y ...int)	// ok
 
-func g(x int, y float) (...)	// ERROR "[.][.][.]" "final argument"
+func g(x int, y float32) (...)	// ERROR "[.][.][.]" "final argument"
 
 func h(x, y ...int)		// ERROR "[.][.][.]"
 
-func i(x int, y ...int, z float)	// ERROR "[.][.][.]"
+func i(x int, y ...int, z float32)	// ERROR "[.][.][.]"
 
 var x ...int;		// ERROR "[.][.][.]|syntax|type"