[Bug c/64610] New: No -Wbool-compare warning on "(0 != a) >= 0"

["chengniansun at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64610

            Bug ID: 64610
           Summary: No -Wbool-compare warning on "(0 != a) >= 0"
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: chengniansun at gmail dot com

There is no warning on the expression "(0 != a) >= 0". I think the cause of
this bug is different from the one I reported just now (PR64609). 


$: cat s.c
int a;
void fn1() { ((0 != a) >= 0); }
$: 
$: gcc-trunk -Wbool-compare -c s.c
$: 
$: clang-trunk -Wno-unused-value -c s.c
s.c:2:24: warning: comparison of constant 0 with boolean expression is always
      true [-Wtautological-constant-out-of-range-compare]
void fn1() { ((0 != a) >= 0); }
              ~~~~~~~~ ^  ~
1 warning generated.
$: 
$: