Add core/hyperthread count for Windows and Linux (#5216)

Add core/hyperthread count to `core:sys/info` for Windows and Linux.
TODO: Linux RISCV, Linux ARM, Darwin, and the BSDs.

core/sys/info/cpu_windows.odin

@@ -0,0 +1,28 @@
+package sysinfo
+
+import sys "core:sys/windows"
+import "base:intrinsics"
+
+@(init, private)
+init_cpu_core_count :: proc() {
+	infos: []sys.SYSTEM_LOGICAL_PROCESSOR_INFORMATION
+	defer delete(infos)
+
+	returned_length: sys.DWORD
+	// Query for the required buffer size.
+	if ok := sys.GetLogicalProcessorInformation(raw_data(infos), &returned_length); !ok {
+		infos = make([]sys.SYSTEM_LOGICAL_PROCESSOR_INFORMATION, returned_length / size_of(sys.SYSTEM_LOGICAL_PROCESSOR_INFORMATION))
+	}
+
+	// If it still doesn't work, return
+	if ok := sys.GetLogicalProcessorInformation(raw_data(infos), &returned_length); !ok {
+		return
+	}
+
+	for info in infos {
+		#partial switch info.Relationship {
+		case .RelationProcessorCore: cpu.physical_cores += 1
+		case .RelationNumaNode:      cpu.logical_cores  += int(intrinsics.count_ones(info.ProcessorMask))
+		}
+	}
+}