Merge pull request #71711 from gottesmm/pr-61de03ca0f96056340596faedebae2193caeb4ac

Remove clang optimize off that snuck into tree.

Author: gottesmm

lib/Serialization/Serialization.cpp

@@ -76,8 +76,6 @@
 
 #define DEBUG_TYPE "Serialization"
 
-#pragma clang optimize off
-
 using namespace swift;
 using namespace swift::serialization;
 using namespace llvm::support;

validation-test/banned_apis/banned_apis.test

@@ -0,0 +1,7 @@
+// This test runs a grep that validates that specific patterns do not occur in
+// the code base.
+
+// The [c] is necessary to prevent substitutions by lit. Same difference since it
+// is just a regex.
+//
+// RUN: cd %swift_src_root && not git grep 'pragma [c]lang optimize off' include lib stdlib