[Performance Hints] Disable performance hints if typechecker skips some function bodies

If `SkipFunctionBodies` is not `None`, functions that are inlinable or not used
for the result are not typechecked. The absence of type information crashes the
performance hint analyzer. This change prevents the analyzer from running in
these cases.

Author: aviralg

lib/Sema/PerformanceHints.cpp

@@ -31,7 +31,8 @@
 using namespace swift;
 
 bool swift::performanceHintDiagnosticsEnabled(ASTContext &ctx) {
-  return !ctx.Diags.isIgnoredDiagnosticGroupTree(DiagGroupID::PerformanceHints);
+  return !ctx.Diags.isIgnoredDiagnosticGroupTree(DiagGroupID::PerformanceHints) &&
+         (ctx.TypeCheckerOpts.SkipFunctionBodies == FunctionBodySkipping::None);
 }
 
 namespace {