Remove irr namespace (#16309)

irr/include/IOSOperator.h

@@ -7,9 +7,6 @@
 #include "IReferenceCounted.h"
 #include "irrString.h"
 
-namespace irr
-{
-
 //! The OSOperator provides OS-specific methods and information.
 class IOSOperator : public virtual IReferenceCounted
 {
@@ -41,5 +38,3 @@ public:
 	\return True if successful, false if not */
 	virtual bool getSystemMemory(u32 *totalBytes, u32 *availableBytes) const = 0;
 };
-
-} // end namespace