[PATCH v3 23/23] x86_64: use relative pointers with dynamic debug

Similar to how x86_64 uses bug_entry-relative pointers to reduce sizeof(struct bug_entry), the same thing can now be done for struct _ddebug, saving 16 bytes for each of those (i.e., each pr_debug, dev_dbg etc. in a CONFIG_DYNAMIC_DEBUG kernel). Note the use of .ifndef/.endif in asm to avoid

[PATCH v3 23/23] x86_64: use relative pointers with dynamic debug

Similar to how x86_64 uses bug_entry-relative pointers to reduce sizeof(struct bug_entry), the same thing can now be done for struct _ddebug, saving 16 bytes for each of those (i.e., each pr_debug, dev_dbg etc. in a CONFIG_DYNAMIC_DEBUG kernel). Note the use of .ifndef/.endif in asm to avoid