loader: detect CPU features

src/kern/amd64/init.zig

@@ -107,7 +107,7 @@ var initial_offsets: [1]usize = .{0};
 extern var __percpu_start: u8;
 
 pub fn early_init() linksection(r.init) void {
-    amd64.detect_cpu_features();
+    amd64.cpu_features = r.boot_info.arch_info.cpu_features;
     early_cpu_init();
 
     impl.cpu_offsets = &initial_offsets;

src/kern/init.zig

@@ -10,6 +10,8 @@ var thread0: ke.Thread = undefined;
 var stack: [r.kib(16)]u8 align(16) = undefined;
 
 pub fn init(boot_info: *r.BootInfo) linksection(r.init) void {
+    r.boot_info = boot_info;
+
     ke.ncpus = 1;
     ki.impl.early_init();
     ki.tunable.init(boot_info);