Revert "avoid capturing weak ref in Pass object"

This reverts commit 36b02d4.

Author: IanButterworth

test/core.jl

@@ -2852,15 +2852,15 @@ mutable struct Obj; x; end
         push!(wr, WeakRef(x))
         nothing
     end
-    @noinline test_wr(r, wr) = r[1] == wr[1].value
+    @noinline test_wr(r, wr) = @test r[1] == wr[1].value
     function test_wr()
         # we need to be very careful here that we never
         # use the value directly in this function, so we aren't dependent
         # on optimizations deleting the root for it before reaching the test
         ref = []
         wref = []
         mk_wr(ref, wref)
-        @test test_wr(ref, wref)
+        test_wr(ref, wref)
         GC.gc()
         test_wr(ref, wref)
         empty!(ref)