[IAST] Use recursive_mutex instead of CS and mutex (#7890)

## Summary of changes
Replaced custom mutex guard with `std::lock_guard`, using
`std::recursive_mutex` instead of `CRITICAL_SECTION` in windows and
`std::mutex` with railings in Linux

## Reason for change
Some locks have been spotted in smoke test wich could be cause by the
lack of thread recursive lock in the `std::mutex`

## Implementation details

## Test coverage

## Other details
<!-- Fixes #{issue} -->


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Author: daniel-romano-DD

tracer/build/_build/Build.Shared.Steps.cs

@@ -310,7 +310,7 @@ partial class Build
             // See also the ValidateNativeProfilerGlibcCompatibility Nuke task and the checks
             // in shared/src/Datadog.Trace.ClrProfiler.Native/cor_profiler.cpp#L1279
             var expectedGlibcVersion = IsArm64
-                ? new Version(2, 18)
+                ? new Version(2, 17)
                 : new Version(2, 17);
 
             var nativeLibHelper = new NativeValidationHelper(Nm, IsAlpine, BuildProjectDirectory);

tracer/src/Datadog.Tracer.Native/iast/hardcoded_secrets_method_analyzer.cpp

@@ -66,7 +66,7 @@ int HardcodedSecretsMethodAnalyzer::GetUserStrings(int arrSize, UserStringIntero
 {
     CSGUARD(_cs);
     _deliveredUserStrings.clear();
-    _deliveredUserStrings.reserve(fmin(arrSize, _userStrings.size()));
+    _deliveredUserStrings.reserve((size_t)fmin(arrSize, _userStrings.size()));
     int x = 0;
     while (x < arrSize && _userStrings.size() > 0)
     {

tracer/src/Datadog.Tracer.Native/iast/iast_util.cpp

@@ -17,87 +17,6 @@ extern char** environ;
 
 namespace iast
 {
-#ifndef _WIN32
-static thread_local std::unordered_map<void *, bool> locked;
-#endif
-    CS::CS()
-    {
-#ifdef _WIN32
-        InitializeCriticalSection(&cs);
-#else
-        locked[this] = false;
-#endif
-    }
-    CS::~CS()
-    {
-#ifdef _WIN32
-        DeleteCriticalSection(&cs);
-#else
-        locked.erase(this); // To avoid uncontrolled map growth
-#endif
-    }
-    bool CS::Lock()
-    {
-#ifdef _WIN32
-        EnterCriticalSection(&cs);
-#else
-        if (locked[this])
-        {
-            return false;
-        }
-        cs.lock();
-        locked[this] = true;
-#endif
-        return true;
-    }
-    void CS::Unlock()
-    {
-#ifdef _WIN32
-        LeaveCriticalSection(&cs);
-#else
-        if (locked[this])
-        {
-            cs.unlock();
-            locked[this] = false;
-        }
-#endif
-    }
-
-    CSGuard::CSGuard(CS* cs) : refs(0)
-    {
-        this->cs = cs;
-        Enter();
-    }
-    CSGuard::~CSGuard()
-    {
-        Leave();
-        cs = nullptr;
-    }
-    void CSGuard::Enter()
-    {
-        if (std::atomic_fetch_add(&refs, 1) == 0)
-        {
-            if (!cs->Lock())
-            {
-                cs = nullptr;
-            }
-        }
-    }
-    void CSGuard::Leave()
-    {
-        if (cs && refs > 0 && std::atomic_fetch_sub(&refs, 1) == 1)
-        {
-            try
-            {
-                cs->Unlock();
-            }
-            catch (...)
-            {
-                /* Ignored */
-            }
-        }
-    }
-
     MatchResult IsMatch(const std::string& exp, const std::string& value)
     {
         return IsMatch(ToWSTRING(exp), ToWSTRING(value));

tracer/src/Datadog.Tracer.Native/iast/iast_util.h

@@ -271,36 +271,8 @@ namespace iast
         }
     };
 
-    class CS
-    {
-    private:
-#ifdef _WIN32
-        CRITICAL_SECTION cs;
-#else
-        std::mutex cs;
-#endif
-    public:
-        CS();
-        virtual ~CS();
-        bool Lock();
-        void Unlock();
-    };
-
-    class CSGuard
-    {
-        CS* cs;
-        std::atomic<int> refs;
-
-    public:
-        CSGuard(CS* cs);
-        virtual ~CSGuard();
-        void Enter();
-        void Leave();
-    };
-
-#define CSGUARD(x) CSGuard __csGuard_##x(&x);
-#define CSENTER(x) __csGuard_##x.Enter();
-#define CSLEAVE(x) __csGuard_##x.Leave();
+#define CS std::recursive_mutex
+#define CSGUARD(x) std::lock_guard<std::recursive_mutex> __csGuard_##x(x);
 
     /////////////////////// Enum Utils /////////////////////////////
 #ifndef BEGIN_ENUM_PARSE