compiler tests: fix using, add tests to make sure instance? inlines

basis/compiler/tests/redefine26.factor

@@ -1,5 +1,5 @@
 USING: accessors classes.tuple classes.maybe compiler.units
-kernel math slots tools.test ;
+kernel math slots tools.test classes.union ;
 IN: compiler.tests.redefine26
 
 TUPLE: yoo ;

basis/compiler/tree/propagation/propagation-tests.factor

@@ -1006,3 +1006,22 @@ M: tuple-with-read-only-slot clone
 [ V{ t } ] [
     [ tag 0 15 between? ] final-literals
 ] unit-test
+
+[ t ] [
+    [ maybe: integer instance? ] { instance? } inlined?
+] unit-test
+
+TUPLE: inline-please a ;
+[ t ] [
+    [ maybe: inline-please instance? ] { instance? } inlined?
+] unit-test
+
+GENERIC: derp ( obj -- obj' )
+
+M: integer derp 5 + ;
+M: f derp drop t ;
+
+[ t ]
+[
+    [ dup maybe: integer instance? [ derp ] when ] { instance? } inlined?
+] unit-test