Defines starting with `a' in kern

• ALLOC_TYPE_ALLOC kern/malloc_debug.h:44
• ALLOC_TYPE_FREE kern/malloc_debug.h:45
• AST_BLOCK kern/ast.h:78
• AST_HALT kern/ast.h:76
• AST_NETIPC kern/ast.h:80
• AST_NETWORK kern/ast.h:79
• AST_PER_THREAD kern/ast.h:94
• AST_SCHEDULING kern/ast.h:83
• AST_TERMINATE kern/ast.h:77
• AST_UNIX kern/ast.h:81
• AST_ZILCH kern/ast.h:75