Merge pull request #79086 from xedin/small-solver-perf-optimizations

[CSOptimizer] A few small performance optimizations

Author: xedin

lib/Sema/CSOptimizer.cpp

@@ -125,6 +125,9 @@ static bool isSupportedDisjunction(Constraint *disjunction) {
   // Non-operator disjunctions are supported only if they don't
   // have any generic choices.
   return llvm::all_of(choices, [&](Constraint *choice) {
+    if (choice->isDisabled())
+      return true;
+
     if (choice->getKind() != ConstraintKind::BindOverload)
       return false;
 
@@ -314,7 +317,13 @@ static void determineBestChoicesInContext(
     if (applicableFn.isNull()) {
       auto *locator = disjunction->getLocator();
       if (auto expr = getAsExpr(locator->getAnchor())) {
-        if (auto *parentExpr = cs.getParentExpr(expr)) {
+        auto *parentExpr = cs.getParentExpr(expr);
+        // Look through optional evaluation, so
+        // we can cover expressions like `a?.b + 2`.
+        if (isExpr<OptionalEvaluationExpr>(parentExpr))
+          parentExpr = cs.getParentExpr(parentExpr);
+
+        if (parentExpr) {
           // If this is a chained member reference or a direct operator
           // argument it could be prioritized since it helps to establish
           // context for other calls i.e. `(a.)b + 2` if `a` and/or `b`

validation-test/Sema/type_checker_perf/fast/swift_package_index_1.swift

@@ -1,4 +1,4 @@
-// RUN: %target-swift-frontend -typecheck %s -solver-scope-threshold=1000
+// RUN: %target-swift-frontend -typecheck %s -solver-scope-threshold=500
 // REQUIRES: tools-release,no_asan
 
 public class Cookie {