Remove bochs breakpoints

arch/x86_64/src/context.rs

@@ -151,8 +151,7 @@ unsafe extern fn signal_handler_wrapper() {
     }
 
     // Push scratch registers
-    asm!("xchg bx, bx
-        push rax
+    asm!("push rax
         push rcx
         push rdx
         push rdi
@@ -171,8 +170,7 @@ unsafe extern fn signal_handler_wrapper() {
     inner(&*(rsp as *const SignalHandlerStack));
 
     // Pop scratch registers, error code, and return
-    asm!("xchg bx, bx
-        pop r11
+    asm!("pop r11
         pop r10
         pop r9
         pop r8

arch/x86_64/src/lib.rs

@@ -241,8 +241,7 @@ macro_rules! interrupt_error {
             }
 
             // Push scratch registers
-            asm!("xchg bx, bx
-                push rax
+            asm!("push rax
                 push rcx
                 push rdx
                 push rdi

arch/x86_64/src/start.rs

@@ -160,8 +160,7 @@ pub unsafe extern fn kstart_ap(cpu_id: usize, bsp_table: usize, stack_start: usi
 
 pub unsafe fn usermode(ip: usize, sp: usize) -> ! {
     // Go to usermode
-    asm!("xchg bx, bx
-        mov ds, ax
+    asm!("mov ds, ax
         mov es, ax
         mov fs, bx
         mov gs, ax