Merge pull request #82320 from xedin/hide-solver-hacks-behind-a-flag

[ConstraintSystem] Guard all the performance hacks with a flag

include/swift/Basic/LangOptions.h

@@ -983,9 +983,6 @@ namespace swift {
     /// is for testing purposes.
     std::vector<std::string> DebugForbidTypecheckPrefixes;
 
-    /// Disable the shrink phase of the expression type checker.
-    bool SolverDisableShrink = false;
-
     /// Enable experimental operator designated types feature.
     bool EnableOperatorDesignatedTypes = false;