Define unified entry points for irq handlers.

The irq entry points now push the handler address and jump to a
    function that does parameter setup.  This reduces the code size
    because the entry setup isn't repeated for every handler.
diff --git a/vgasrc/vgaentry.S b/vgasrc/vgaentry.S
index 48264cf..7802bdb 100644
--- a/vgasrc/vgaentry.S
+++ b/vgasrc/vgaentry.S
@@ -40,4 +40,7 @@
         ENTRY_ARG vga_post
-        DECL_IRQ_ENTRY_ARG 10
+        DECLFUNC entry_10
+        ENTRY_ARG handle_10
+        iretw