RP2040: Fix use of deprecated volatile semantics for C++20 (#1318) (#1319)

Co-authored-by: Mathias Gredal <matg@universal-robots.com>
Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>

portable/ThirdParty/GCC/Posix/port.c

@@ -229,6 +229,7 @@ StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack,
     /* Ensure that there is enough space to store Thread_t on the stack. */
     ulStackSize = ( size_t ) ( pxTopOfStack + 1 - pxEndOfStack ) * sizeof( *pxTopOfStack );
     configASSERT( ulStackSize > sizeof( Thread_t ) );
+    ( void ) ulStackSize; /* suppress set but not used warning */
 
     thread->pxCode = pxCode;
     thread->pvParams = pvParameters;

portable/ThirdParty/GCC/RP2040/include/portmacro.h

@@ -227,7 +227,7 @@ static inline void vPortRecursiveLock( BaseType_t xCoreID,
             if( ucOwnedByCore[ xCoreID ][ ulLockNum ] )
             {
                 configASSERT( ucRecursionCountByLock[ ulLockNum ] != 255u );
-                ucRecursionCountByLock[ ulLockNum ]++;
+                ucRecursionCountByLock[ ulLockNum ] = ucRecursionCountByLock[ ulLockNum ] + 1;
                 return;
             }
             spin_lock_unsafe_blocking(pxSpinLock);
@@ -241,7 +241,8 @@ static inline void vPortRecursiveLock( BaseType_t xCoreID,
         configASSERT( ( ucOwnedByCore[ xCoreID ] [ulLockNum ] ) != 0 );
         configASSERT( ucRecursionCountByLock[ ulLockNum ] != 0 );
 
-        if( !--ucRecursionCountByLock[ ulLockNum ] )
+        ucRecursionCountByLock[ ulLockNum ] = ucRecursionCountByLock[ ulLockNum ] - 1;
+        if ( ucRecursionCountByLock[ ulLockNum ] == 0U )
         {
             ucOwnedByCore[ xCoreID ] [ ulLockNum ] = 0;
             spin_unlock_unsafe(pxSpinLock);