Add `G_GNUC_UNUSED` flag for the GCC warnings.

BUG=ibus#2805

Wish to run ibus-daemon after run ibus-ui-gtk3 for the debug purpose.

BUG=ibus#2805

- When malloc() is failed, the pointer should not be deallocated
  and also other allocated memory pointers should be freed in FrameMgr.c.
- The `XIM_STRFUNC` macro implemented in XimProto.h.
- GCC `-Wanalyzer-malloc-leak` flag does not have to warn the reallocation
  since the `address` pointer is not changed and `address->imvalue_mask`
  should work in i18nMethod.c
- Seems GCC does not understand `if (!p->value)` and replace it with a
  wrapper variable in i18nMethod.c
- Fix exit() from within signal handler by CWE-479 and
  `-Wanalyzer-unsafe-call-within-signal-handler` in client/x11/main.c

BUG=ibus#2805

Fix leaks of GOptionContext in bus/main.c

BUG=ibus#2805

Fix leaks of GOptionContext in bus/main.c
Fix leaks of IBusEngineDesc when IME is switched in
client/wayland/ibuswaylandim.c

BUG=ibus#2805

- Fix leaks of GOptionContext in bus/main.c
- Fix leaks of IBusEngineDesc when IME is switched in
  client/wayland/ibuswaylandim.c
- Fix leaks of IBusTextClass:copy(), which is used in
  Emojier:get_one_dimension_lookup_table(), in src/ibustext.c
- Fix leak of IBusExtensionEvent with commit-text signal and clicking close
  button since it's not floating in ui/gtk3/panelbinding.vala

Fixes: ibus@a800957
BUG=ibus#2805

- When malloc() is failed, the pointer should not be deallocated
  and also other allocated memory pointers should be freed in FrameMgr.c.
- The `XIM_STRFUNC` macro implemented in XimProto.h.
- GCC `-Wanalyzer-malloc-leak` flag does not have to warn the reallocation
  since the `address` pointer is not changed and `address->imvalue_mask`
  should work in i18nMethod.c
- Seems GCC does not understand `if (!p->value)` and replace it with a
  wrapper variable in i18nMethod.c
- Fix exit() from within signal handler by CWE-479 and
  `-Wanalyzer-unsafe-call-within-signal-handler` in client/x11/main.c

BUG=ibus#2805

- Fix leaks of GOptionContext in bus/main.c
- Fix leaks of IBusEngineDesc when IME is switched in
  client/wayland/ibuswaylandim.c
- Fix leaks of IBusTextClass:copy(), which is used in
  Emojier:get_one_dimension_lookup_table(), in src/ibustext.c
- Fix leak of IBusExtensionEvent with commit-text signal and clicking close
  button since it's not floating in ui/gtk3/panelbinding.vala

Fixes: ibus@a800957
BUG=ibus#2805

Add `G_GNUC_UNUSED` flag for the GCC warnings.

BUG=#2805

Wish to run ibus-daemon after run ibus-ui-gtk3 for the debug purpose.

BUG=#2805

- When malloc() is failed, the pointer should not be deallocated
  and also other allocated memory pointers should be freed in FrameMgr.c.
- The `XIM_STRFUNC` macro implemented in XimProto.h.
- GCC `-Wanalyzer-malloc-leak` flag does not have to warn the reallocation
  since the `address` pointer is not changed and `address->imvalue_mask`
  should work in i18nMethod.c
- Seems GCC does not understand `if (!p->value)` and replace it with a
  wrapper variable in i18nMethod.c
- Fix exit() from within signal handler by CWE-479 and
  `-Wanalyzer-unsafe-call-within-signal-handler` in client/x11/main.c

BUG=#2805

- Fix leaks of GOptionContext in bus/main.c
- Fix leaks of IBusEngineDesc when IME is switched in
  client/wayland/ibuswaylandim.c
- Fix leaks of IBusTextClass:copy(), which is used in
  Emojier:get_one_dimension_lookup_table(), in src/ibustext.c
- Fix leak of IBusExtensionEvent with commit-text signal and clicking close
  button since it's not floating in ui/gtk3/panelbinding.vala

Fixes: a800957
BUG=#2805