Fix build with clang 6.

The fix also causes the port to fail on 10.x, so add USES-compiler
and USE_CXXSTD=c++11 to address that problem too.

PR:		225835
Submitted by:	Thibault Payet <monwarez@mailoo.org> (maintainer)

games/torcs/Makefile

@@ -19,12 +19,13 @@ RUN_DEPENDS=	bash:shells/bash
 
 MAKE_JOBS_UNSAFE=	yes
 
-USES=		cpe gmake openal:al,alut shebangfix tar:bzip2
+USES=		compiler:c++11-lang cpe gmake openal:al,alut shebangfix tar:bzip2
 CPE_VENDOR=	bernhard_wymann
 SHEBANG_FILES=	src/tools/accc/accc.in src/tools/nfsperf/nfsperf.in \
 		src/tools/texmapper/texmapper.in src/tools/nfs2ac/nfs2ac.in \
 		src/tools/trackgen/trackgen.in \
 		src/modules/telemetry/telemetry.sh robotgen
+USE_CXXSTD=	c++11
 USE_XORG=	xrender xmu ice xext x11 xxf86vm xrandr xi xt sm
 USE_GL=		glut glu gl
 GNU_CONFIGURE=	yes

games/torcs/files/patch-Make-default.mk

@@ -9,3 +9,12 @@
  
  dep:	.depend
  
+@@ -181,7 +181,7 @@ win32setup: win32start exportswin32 installshipswin32 
+ 
+ linuxconfstart:
+ 	@rm -f ${SETUP_LINUX}
+-	@echo '#! /bin/bash' >> ${SETUP_LINUX}
++	@echo '#! /usr/local/bin/bash' >> ${SETUP_LINUX}
+ 	@echo '' >> ${SETUP_LINUX}
+ 	@echo '[ -z "$$1" ] && exit 1' >> ${SETUP_LINUX}
+ 	@echo '[ ! -d "$$1" ] && exit 1' >> ${SETUP_LINUX}

games/torcs/files/patch-src_drivers_olethros_driver.cpp

@@ -0,0 +1,11 @@
+--- src/drivers/olethros/driver.cpp.orig	2018-02-11 21:23:59 UTC
++++ src/drivers/olethros/driver.cpp
+@@ -802,7 +802,7 @@ namespace olethros {
+             rpmMaxTq,
+             rpmMaxPw,
+             rpmMax,
+-            rpmMax*2.0
++            rpmMax*2.0f
+ 	};
+ 	int N = 5;
+ 	for (int i=0; i<N - 1; i++) {

games/torcs/files/patch-src_libs_musicplayer_OpenALMusicPlayer.cpp

@@ -0,0 +1,18 @@
+--- src/libs/musicplayer/OpenALMusicPlayer.cpp.orig	2018-02-11 19:14:32 UTC
++++ src/libs/musicplayer/OpenALMusicPlayer.cpp
+@@ -161,7 +161,7 @@ bool OpenALMusicPlayer::streamBuffer(ALuint buffer)
+ {
+ 	char pcm[BUFFERSIZE];
+ 	int size = 0;
+-	const char* error = '\0';
++	const char* error = nullptr;
+ 	
+ 	if (!stream->read(pcm, BUFFERSIZE, &size, &error)) {
+ 		GfError("OpenALMusicPlayer: Stream read error: %s\n", error);
+@@ -268,4 +268,4 @@ bool OpenALMusicPlayer::startPlayback()
+     alSourcePlay(source);
+     
+     return true;
+-}
+\ No newline at end of file
++}