Fixed flag description

[vitalybuka]

Summary

asan-use-after-return control feature we call use-after-return or
stack-use-after-return.

[eugenis]

LGTM

[vitalybuka]

Can you please land this patch.

[aizatsky]

on it.

llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp

 static cl::opt<int> ClMaxInsnsToInstrumentPerBB(
     "asan-max-ins-per-bb", cl::init(10000),
     cl::desc("maximal number of instructions to instrument in any given BB"),
     cl::Hidden);
 // This flag may need to be replaced with -f[no]asan-stack.
 static cl::opt<bool> ClStack("asan-stack", cl::desc("Handle stack memory"),
                              cl::Hidden, cl::init(true));
 static cl::opt<bool> ClUseAfterReturn("asan-use-after-return",
-                                      cl::desc("Check return-after-free"),
+                                      cl::desc("Check stack-use-after-return"),
                                       cl::Hidden, cl::init(true));
 static cl::opt<bool> ClUseAfterScope("asan-use-after-scope",
                                      cl::desc("Check stack-use-after-scope"),
                                      cl::Hidden, cl::init(false));
 // This flag may need to be replaced with -f[no]asan-globals.
 static cl::opt<bool> ClGlobals("asan-globals",
                                cl::desc("Handle global objects"), cl::Hidden,
                                cl::init(true));

 // supported on recent versions of ld64.
 bool AddressSanitizerModule::ShouldUseMachOGlobalsSection() const {
   if (!TargetTriple.isOSBinFormatMachO())
     return false;
 
   if (TargetTriple.isMacOSX() && !TargetTriple.isMacOSXVersionLT(10, 11))
     return true;
   if (TargetTriple.isiOS() /* or tvOS */ && !TargetTriple.isOSVersionLT(9))
-    return true;  
+    return true;
   if (TargetTriple.isWatchOS() && !TargetTriple.isOSVersionLT(2))
     return true;
 
   return false;
 }
 
 void AddressSanitizerModule::initializeCallbacks(Module &M) {
   IRBuilder<> IRB(*C);
void AddressSanitizerModule::initializeCallbacks(Module &M) {
   AsanUnregisterGlobals->setLinkage(Function::ExternalLinkage);
 
   // Declare the functions that find globals in a shared object and then invoke
   // the (un)register function on them.
   AsanRegisterImageGlobals = checkSanitizerInterfaceFunction(
       M.getOrInsertFunction(kAsanRegisterImageGlobalsName,
       IRB.getVoidTy(), IntptrTy, nullptr));
   AsanRegisterImageGlobals->setLinkage(Function::ExternalLinkage);
-  
   AsanUnregisterImageGlobals = checkSanitizerInterfaceFunction(
       M.getOrInsertFunction(kAsanUnregisterImageGlobalsName,
       IRB.getVoidTy(), IntptrTy, nullptr));
   AsanUnregisterImageGlobals->setLinkage(Function::ExternalLinkage);
 }
 
 // This function replaces all global variables with new variables that have
 // trailing redzones. It also creates a function that poisons