[Bug c/64609] New: No -Wbool-compare warning on "(a = 0 && 0) <= 4"

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64609

            Bug ID: 64609
           Summary: No -Wbool-compare warning on "(a = 0 && 0) <= 4"
           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

This might not be a bug, but a feature request. There is no -Wbool-compare
warning for the following code. 

$: cat s.c
int a;
void fn1() { ((a = 0 && 0) <= 4); }
$: 
$: gcc-trunk -c s.c -Wbool-compare
$: 
$: clang-trunk -c s.c -Wno-unused-value
s.c:2:28: warning: comparison of constant 4 with boolean expression is always
      true [-Wtautological-constant-out-of-range-compare]
void fn1() { ((a = 0 && 0) <= 4); }
              ~~~~~~~~~~~~ ^  ~
1 warning generated.
$: 
$: