Change complex number val() tests.

On second thought, it seems that stacking signs like was being tested
isn't all that useful, so the tests in question have been changed to
testing a different kind of complex number (one using Inf in the
imaginary part).

S02-literals/allomorphic.t

@@ -98,14 +98,14 @@ lives-ok {val("foo")}, "val() exists";
 }
 
 {
-    my $cmpxval = val(" +1.0+-3.2i ");
+    my $cmpxval = val(" +1.0-Inf\\i ");
 
-    isa-ok $cmpxval, ComplexStr, "val(\" +1.0+-3.2i \") returns a ComplexStr";
-    isa-ok $cmpxval, Complex,    "val(\" +1.0+-3.2i \") can be a Complex";
-    isa-ok $cmpxval, Str,        "val(\" +1.0+-3.2i \") can be a Str";
+    isa-ok $cmpxval, ComplexStr, Q[val(" +1.0-Inf\\i ") returns a ComplexStr];
+    isa-ok $cmpxval, Complex,    Q[val(" +1.0-Inf\\i ") can be a Complex];
+    isa-ok $cmpxval, Str,        Q[val(" +1.0-Inf\\i ") can be a Str];
 
-    is +$cmpxval, (1-3.2i), "val(\" +1.0+-3.2i \") is equal to complex number 1-3.2i";
-    is ~$cmpxval, " +1.0+-3.2i ", "val(\" +1.0+-3.2i \") is equal to string \" +1.0+-3.2i \"";
+    is +$cmpxval, (1-Inf\i), Q[val(" +1.0-Inf\\i ") is equal to complex number 1-Inf\i];
+    is ~$cmpxval, " +1.0-Inf\\i ", Q[val(" +1.0-Inf\\i ") is equal to string " +1.0-Inf\\i "];
 }
 
 # Note: L<S02/The :val modifier> seems to suggest that version literals and