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/crypto/_chacha20/simd128/chacha20_simd128.odin

@@ -227,7 +227,7 @@ is_performant :: proc "contextless" () -> bool {
 			req_features :: info.CPU_Features{.V}
 		}
 
-		features, ok := info.cpu_features.?
+		features, ok := info.cpu.features.?
 		if !ok {
 			return false
 		}

core/crypto/_chacha20/simd256/chacha20_simd256.odin

@@ -41,7 +41,7 @@ _VEC_TWO: simd.u64x4 : {2, 0, 2, 0}
 is_performant :: proc "contextless" () -> bool {
 	req_features :: info.CPU_Features{.avx, .avx2}
 
-	features, ok := info.cpu_features.?
+	features, ok := info.cpu.features.?
 	if !ok {
 		return false
 	}