Silence C warnings

-w got lost in the port from Autotools to Vala. We shouldn't emit C
compiler warnings because this isn't a C project.

engine/meson.build

@@ -11,6 +11,7 @@ libengine_vala_args = [
 
 libengine_c_args = [
   '-include', 'config.h',
+  '-w'
 ]
 
 libengine_deps = [

lib/meson.build

@@ -16,6 +16,7 @@ libchess_vala_args = [
 
 libchess_c_args = [
   '-include', 'config.h',
+  '-w'
 ]
 
 libchess_deps = [

src/meson.build

@@ -18,6 +18,7 @@ chess_vala_args = [
 
 chess_c_args = [
   '-include', 'config.h',
+  '-w'
 ]
 
 chess_deps = [

tests/meson.build

@@ -9,6 +9,7 @@ tests_vala_args = [
 
 tests_c_args = [
   '-include', 'config.h',
+  '-w'
 ]
 
 tests_deps = [