add vxbuild-cross support

csrc/libb64/build-linux32.sh

@@ -0,0 +1 @@
+P=linux32 C="-m32 -fPIC" L="-m32 -s -static-libgcc" D=libb64.so A=libb64.a ./build.sh

csrc/libb64/build-linux64.sh

@@ -1 +1 @@
-P=linux64 C=-fPIC L="-s -static-libgcc" D=libb64.so A=libb64.a ./build.sh
+P=linux64 C="-fPIC" L="-s -static-libgcc" D=libb64.so A=libb64.a ./build.sh

csrc/libb64/build-mingw32.sh

@@ -0,0 +1,2 @@
+[ `uname` = Linux ] && { export X=i686-w64-mingw32-; }
+P=mingw32 C="-fPIC" L="-s -static-libgcc" D=b64.dll A=b64.a ./build.sh

csrc/libb64/build-mingw64.sh

@@ -1 +1,2 @@
-P=mingw64 L="-s -static-libgcc" D=b64.dll A=b64.a ./build.sh
+[ `uname` = Linux ] && { export X=x86_64-w64-mingw32-; }
+P=mingw64 C="-fPIC" L="-s -static-libgcc" D=b64.dll A=b64.a ./build.sh

csrc/libb64/build-osx64.sh

@@ -1,3 +1,3 @@
-[ `uname` = Linux ] && export X=x86_64-apple-darwin11-
-P=osx64 C="-arch x86_64" L="-arch x86_64 -install_name @rpath/libb64.dylib" \
+[ `uname` = Linux ] && { export X=x86_64-apple-darwin19-; export CC=clang; }
+P=osx64 C="-arch x86_64 -fPIC" L="-arch x86_64 -install_name @rpath/libb64.dylib" \
 	D=libb64.dylib A=libb64.a ./build.sh

csrc/libb64/build.sh

@@ -1,5 +1,7 @@
-${X}gcc -c -O2 $C *.c -Wall -I.
-${X}gcc *.o -shared -o ../../bin/$P/$D $L
+[ "$CC" ] || CC=gcc
+mkdir -p ../../bin/$P
+${X}${CC} -c -O2 $C *.c -Wall -I.
+${X}${CC} *.o -shared -o ../../bin/$P/$D $L
 rm -f      ../../bin/$P/$A
 ${X}ar rcs ../../bin/$P/$A *.o
 rm *.o