[bindings] Fix genbindings.sh compile issues on OSX

There were two issues on OSX - we need to give gcc the clang
warnings flags because `gcc` *is* clang on OSX and we missed an
`-std=c++11` on one of the clang++ calls, causing compile failures.

Author: TheBlueMatt

genbindings.sh

@@ -47,24 +47,24 @@ fi
 
 # Finally, sanity-check the generated C and C++ bindings with demo apps:
 
+CFLAGS="-Wall -Wno-nullability-completeness -pthread"
+
 # Naively run the C demo app:
-gcc -Wall -g -pthread demo.c target/debug/libldk.a -ldl
+gcc $CFLAGS -Wall -g -pthread demo.c target/debug/libldk.a -ldl
 ./a.out
 
 # And run the C++ demo app in valgrind to test memory model correctness and lack of leaks.
-g++ -std=c++11 -Wall -g -pthread demo.cpp -Ltarget/debug/ -lldk -ldl
+g++ $CFLAGS -std=c++11 -Wall -g -pthread demo.cpp -Ltarget/debug/ -lldk -ldl
 if [ -x "`which valgrind`" ]; then
 	LD_LIBRARY_PATH=target/debug/ valgrind --error-exitcode=4 --memcheck:leak-check=full --show-leak-kinds=all ./a.out
 	echo
 else
 	echo "WARNING: Please install valgrind for more testing"
 fi
 
-CLANGOPTS="-Wall -Wno-nullability-completeness -pthread"
-
 # Test a statically-linked C++ version, tracking the resulting binary size and runtime
 # across debug, LTO, and cross-language LTO builds (using the same compiler each time).
-clang++ $CLANGOPTS demo.cpp target/debug/libldk.a -ldl
+clang++ $CFLAGS -std=c++11 demo.cpp target/debug/libldk.a -ldl
 strip ./a.out
 echo " C++ Bin size and runtime w/o optimization:"
 ls -lha a.out
@@ -85,11 +85,11 @@ if [ "$HOST_PLATFORM" = "host: x86_64-unknown-linux-gnu" ]; then
 			set +e
 
 			# First the C demo app...
-			clang-$LLVM_V $CLANGOPTS -fsanitize=memory -fsanitize-memory-track-origins -g demo.c target/debug/libldk.a -ldl
+			clang-$LLVM_V $CFLAGS -fsanitize=memory -fsanitize-memory-track-origins -g demo.c target/debug/libldk.a -ldl
 			./a.out
 
 			# ...then the C++ demo app
-			clang++-$LLVM_V -std=c++11 $CLANGOPTS -fsanitize=memory -fsanitize-memory-track-origins -g demo.cpp target/debug/libldk.a -ldl
+			clang++-$LLVM_V $CFLAGS -std=c++11 -fsanitize=memory -fsanitize-memory-track-origins -g demo.cpp target/debug/libldk.a -ldl
 			./a.out >/dev/null
 
 			# restore exit-on-failure
@@ -155,11 +155,11 @@ if [ "$HOST_PLATFORM" = "host: x86_64-unknown-linux-gnu" -o "$HOST_PLATFORM" = "
 		mv Cargo.toml.bk Cargo.toml
 
 		# First the C demo app...
-		$CLANG $CLANGOPTS -fsanitize=address -g demo.c target/debug/libldk.a -ldl
+		$CLANG $CFLAGS -fsanitize=address -g demo.c target/debug/libldk.a -ldl
 		ASAN_OPTIONS='detect_leaks=1 detect_invalid_pointer_pairs=1 detect_stack_use_after_return=1' ./a.out
 
 		# ...then the C++ demo app
-		$CLANGPP $CLANGOPTS -std=c++11 -fsanitize=address -g demo.cpp target/debug/libldk.a -ldl
+		$CLANGPP $CFLAGS -std=c++11 -fsanitize=address -g demo.cpp target/debug/libldk.a -ldl
 		ASAN_OPTIONS='detect_leaks=1 detect_invalid_pointer_pairs=1 detect_stack_use_after_return=1' ./a.out >/dev/null
 	else
 		echo "WARNING: Please install clang-$RUSTC_LLVM_V and clang++-$RUSTC_LLVM_V to build with address sanitizer"
@@ -170,7 +170,7 @@ fi
 
 # Now build with LTO on on both C++ and rust, but without cross-language LTO:
 CARGO_PROFILE_RELEASE_LTO=true cargo rustc -v --release -- -C lto
-clang++ $CLANGOPTS -std=c++11 -flto -O2 demo.cpp target/release/libldk.a -ldl
+clang++ $CFLAGS -std=c++11 -flto -O2 demo.cpp target/release/libldk.a -ldl
 strip ./a.out
 echo "C++ Bin size and runtime with only RL (LTO) optimized:"
 ls -lha a.out
@@ -183,7 +183,7 @@ if [ "$HOST_PLATFORM" != "host: x86_64-apple-darwin" -a "$CLANGPP" != "" ]; then
 	# packaging than simply shipping the rustup binaries (eg Debian should Just Work
 	# here).
 	CARGO_PROFILE_RELEASE_LTO=true cargo rustc -v --release -- -C linker-plugin-lto -C lto -C link-arg=-fuse-ld=lld
-	$CLANGPP $CLANGOPTS -flto -fuse-ld=lld -O2 demo.cpp target/release/libldk.a -ldl
+	$CLANGPP $CFLAGS -flto -fuse-ld=lld -O2 demo.cpp target/release/libldk.a -ldl
 	strip ./a.out
 	echo "C++ Bin size and runtime with cross-language LTO:"
 	ls -lha a.out