scheduler: Work around GCC2 limitations in function inlining

GCC2 won't inline a function if it is used before its definition.

headers/private/kernel/smp.h

@@ -41,7 +41,7 @@ typedef void (*smp_call_func)(addr_t data1, int32 currentCPU, addr_t data2, addr
 
 class CPUSet {
 public:
-						CPUSet() { ClearAll(); }
+	inline				CPUSet();
 
 	inline	void		ClearAll();
 	inline	void		SetAll();
@@ -92,6 +92,13 @@ int smp_intercpu_int_handler(int32 cpu);
 #endif
 
 
+inline
+CPUSet::CPUSet()
+{
+	memset(fBitmap, 0, sizeof(fBitmap));
+}
+
+
 inline void
 CPUSet::ClearAll()
 {