No specialization when library function is renamed.

[gambiteer]

With this test-file

(declare (standard-bindings)
         (extended-bindings)
         (block)
         (mostly-fixnum)
         (not safe))

(define u64-and bitwise-and)

(define (foo x y)
  (u64-and x y))

foo is compiled as

#undef ___PH_PROC
#define ___PH_PROC ___H_foo
#undef ___PH_LBL0
#define ___PH_LBL0 3
#undef ___PD_ALL
#define ___PD_ALL ___D_FP
#undef ___PR_ALL
#define ___PR_ALL ___R_FP
#undef ___PW_ALL
#define ___PW_ALL
___BEGIN_P_COD
___BEGIN_P_HLBL
___DEF_P_HLBL_INTRO
___DEF_P_HLBL(___L0_foo)
___DEF_P_HLBL(___L1_foo)
___END_P_HLBL
___BEGIN_P_SW
___DEF_SLBL(0,___L0_foo)
   ___IF_NARGS_EQ(2,___NOTHING)
   ___WRONG_NARGS(0,2,0,0)
___DEF_GLBL(___L_foo)
   ___POLL(1)
___DEF_SLBL(1,___L1_foo)
   ___JUMPPRM(___SET_NARGS(2),___PRM__23__23_bitwise_2d_and)
___END_P_SW
___END_P_COD

i.e., when u64-and is replaced by bitwise-and, the bitwise-and is not specialized for the two-fixnum case.