games/gtkradiant: try to fix the port's build against Clang 16

Ancient `register' keyword is gone with C++17, drop it from various
places.  Also, ISO C99 and later no longer tolerate implicit function
declarations, but the code in question is too convoluted and fragile
to fix properly, so just disable the warning for the time being.

While here, do not hardcode -O2 for release builds (system-provided
compilation flags being correctly upheld) and spell -Wextra correctly
(quoting the GCC docs*, this option used to be called -W; the older
name is still supported, but the newer name is more descriptive).

Reported by:	pkg-fallout

*) https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#index-Wextra

games/gtkradiant/Makefile

@@ -19,7 +19,7 @@ LIB_DEPENDS=	libgtkglext-x11-1.0.so:x11-toolkits/gtkglext \
 		libpng.so:graphics/png
 
 USES=		compiler:c++11-lang gnome pkgconfig python:build scons zip
-USE_GNOME=	gtk20 libxml2
+USE_GNOME=	gdkpixbuf2 gtk20 libxml2
 MAKE_ARGS=	${MAKE_ENV} BUILD=release
 SSP_UNSAFE=	yes
 
@@ -44,7 +44,13 @@ post-patch:
 		${WRKSRC}/radiant/patch.cpp \
 		${WRKSRC}/radiant/watchbsp.cpp \
 		${WRKSRC}/tools/quake3/common/inout.c
-# Fix the build against Clang
+# Fix the build against Clang and possibly other modern compilers
+	@${REINPLACE_CMD} -e 's,register ,,g' \
+		${WRKSRC}/libs/container/hashfunc.h \
+		${WRKSRC}/libs/jpeg6/jdcolor.cpp \
+		${WRKSRC}/libs/jpeg6/jdhuff.* \
+		${WRKSRC}/libs/jpeg6/jdsample.cpp \
+		${WRKSRC}/libs/jpeg6/jutils.cpp
 	@${REINPLACE_CMD} -e '/#include "generic\/reference\.h"/x ; 318G' \
 		${WRKSRC}/libs/scenelib.h
 	@${REINPLACE_CMD} -e '/#include "generic\/referencecounted\.h/ { \

games/gtkradiant/files/patch-SConstruct

@@ -121,20 +121,23 @@
  p = pickle.Pickler(site_file)
  p.dump(site_dict)
  site_file.close()
-@@ -172,8 +166,8 @@ LINK = CXX
+@@ -170,7 +164,7 @@ SetOption('num_jobs', JOBS)
+ 
+ LINK = CXX
  # common flags
- warningFlags = '-W -Wall -Wcast-align -Wcast-qual -Wno-unused-parameter '
+-warningFlags = '-W -Wall -Wcast-align -Wcast-qual -Wno-unused-parameter '
++warningFlags = '-Wall -Wextra -Wcast-align -Wcast-qual -Wno-implicit-function-declaration -Wno-unused-parameter '
  warningFlagsCXX = '-Wno-non-virtual-dtor -Wreorder ' # -Wold-style-cast
--CCFLAGS = '' + warningFlags
--CXXFLAGS = '-pipe -DQ_NO_STLPORT ' + warningFlags + warningFlagsCXX
-+CCFLAGS += ' '
-+CXXFLAGS += ' -pipe -DQ_NO_STLPORT '
- CPPPATH = []
- if (BUILD == 'debug'):
+ CCFLAGS = '' + warningFlags
+ CXXFLAGS = '-pipe -DQ_NO_STLPORT ' + warningFlags + warningFlagsCXX
+@@ -179,18 +173,17 @@ if (BUILD == 'debug'):
  	CXXFLAGS += '-g -D_DEBUG '
-@@ -182,15 +176,14 @@ elif (BUILD == 'release'):
- 	CXXFLAGS += '-O2 '
- 	CCFLAGS += '-O2 '
+ 	CCFLAGS += '-g -D_DEBUG '
+ elif (BUILD == 'release'):
+-	CXXFLAGS += '-O2 '
+-	CCFLAGS += '-O2 '
++	# uphold system-provided compilation flags
++	pass
  elif ( BUILD == 'info' ):
 -	print 'Preparing OSX release'
 +	print('Preparing OSX release')