B3::ReduceStrength is overly conservative at applying specializeSelect

https://bugs.webkit.org/show_bug.cgi?id=270577
rdar://124146878

Reviewed by Justin Michaud.

Right now it only applies if both outputs from a select are constant. The comment
and testing indicates this is profitable as long as one of the two outputs is a constant.
This looks like a 1.7% speedup on JS3.

* Source/JavaScriptCore/b3/B3ReduceStrength.cpp:

Canonical link: https://commits.webkit.org/275765@main

Source/JavaScriptCore/b3/B3ReduceStrength.cpp

@@ -2502,7 +2502,7 @@ class ReduceStrength {
                 m_value->child(0), selectSpecializationBound,
                 [&] (Value* value) -> bool {
                     return value->opcode() == Select
-                        && (value->child(1)->isConstant() && value->child(2)->isConstant());
+                        && (value->child(1)->isConstant() || value->child(2)->isConstant());
                 });
 
             if (select) {