ke: add generic IPI mechanism

src/kern/amd64/impl.zig

@@ -113,14 +113,6 @@ pub inline fn restore_interrupts(state: bool) void {
     }
 }
 
-pub inline fn send_resched_ipi(target: u32) void {
-    pl.impl.send_resched_ipi(target);
-}
-
-pub inline fn send_tlb_ipi(target: u32) void {
-    pl.impl.send_tlb_ipi(target);
-}
-
 pub inline fn flush_full_tlb() void {
     const prev_cr3 = amd64.read_cr(3);
     // Reload CR3 to flush the entire TLB.

src/kern/amd64/int.zig

@@ -85,8 +85,9 @@ export fn isr_handler_main(frame: *const amd64.IrqFrame) callconv(.{ .x86_64_sys
         ki.timer.clock();
     }
 
-    if (frame.intno == 241) {
-        ki.shootdown.ipi_handler();
+    // Platform IPI number.
+    if (frame.intno == 240) {
+        ki.ipi.ipi_handler();
     }
 
     if (frame.intno >= 32) {