add get core count

core/sys/windows/kernel32.odin

@@ -370,6 +370,8 @@ foreign kernel32 {
 		lpTotalNumberOfBytes: PULARGE_INTEGER,
 		lpTotalNumberOfFreeBytes: PULARGE_INTEGER,
 	) -> BOOL ---
+
+	GetLogicalProcessorInformation :: proc(buffer: ^LOGICAL_PROCESSOR_INFORMATION, returnedLength: PDWORD) -> BOOL ---
 }
 
 
@@ -999,3 +1001,45 @@ foreign kernel32 {
 	ConvertThreadToFiber :: proc(lpParameter: LPVOID) -> LPVOID ---
 	SwitchToFiber :: proc(lpFiber: LPVOID) ---
 }
+
+LOGICAL_PROCESSOR_RELATIONSHIP :: enum c_int {
+	RelationProcessorCore,
+	RelationNumaNode,
+	RelationCache,
+	RelationProcessorPackage,
+	RelationGroup,
+	RelationProcessorDie,
+	RelationNumaNodeEx,
+	RelationProcessorModule,
+	RelationAll = 0xffff,
+}
+
+PROCESSOR_CACHE_TYPE :: enum c_int {
+	CacheUnified,
+	CacheInstruction,
+	CacheData,
+	CacheTrace,
+}
+
+CACHE_DESCRIPTOR :: struct {
+	Level: BYTE,
+	Associativity: BYTE,
+	LineSize: WORD,
+	Size: DWORD,
+	Type: PROCESSOR_CACHE_TYPE,
+}
+
+SYSTEM_LOGICAL_PROCESSOR_INFORMATION :: struct {
+	ProcessorMask: ULONGPTR,
+	Relationship: LOGICAL_PROCESSOR_RELATIONSHIP,
+	DUMMYUNIONNAME :: union {
+		ProcessorCore :: struct {
+			Flags: BYTE,
+		},
+		NumaNode :: struct {
+			NodeNumber: DWORD,
+		},
+		Cache: CACHE_DESCRIPTOR,
+		Reserved: [2]ULONGLONG,
+	},
+}