Missed Optimization: failure to simplify (|x| + |y|) == 0 into (x == 0) && (y == 0)

```llvm
define i1 @src(i32 %arg2, i32 %arg3, ptr %arg0, ptr %arg1) {
%v0 = add nsw i32 %arg3, %arg2
%v1 = sext i32 %v0 to i64
%v2 = getelementptr inbounds double, ptr %arg1, i64 %v1
%v3 = load double, ptr %v2, align 8
%v4 = fcmp oge double %v3, 0.000000e+00
%v5 = fneg double %v3
%v6 = select i1 %v4, double %v3, double %v5
%v7 = load double, ptr %arg0, align 8
%v8 = fcmp oge double %v7, 0.000000e+00
%v9 = fneg double %v7
%v10 = select i1 %v8, double %v7, double %v9
%v11 = fadd double %v6, %v10
%v12 = fcmp oeq double %v11, 0.000000e+00
ret i1 %v12
}

define i1 @tgt(i32 %arg3, i32 %arg2, ptr %arg0, ptr %arg1) {
%v0 = add nsw i32 %arg3, %arg2
%v1 = sext i32 %v0 to i64
%v2 = getelementptr inbounds double, ptr %arg1, i64 %v1
%v3 = load double, ptr %v2, align 8
%v7 = load double, ptr %arg0, align 8
%cmp1 = fcmp oeq double %v3, 0.000000e+00
%cmp2 = fcmp oeq double %v7, 0.000000e+00
%res = and i1 %cmp1, %cmp2
ret i1 %res
}
```

alive2: https://alive2.llvm.org/ce/z/fiaFeZ
godbolt: https://godbolt.org/z/Tnqfc7z9c

Pattern found in: https://github.com/dtcxzyw/llvm-opt-benchmark/blob/main/bench/openblas/optimized/dhseqr.ll