supercollider: fix musl build

srcpkgs/supercollider/patches/musl-implement-correct-xsi.patch

@@ -0,0 +1,18 @@
+--- external_libraries/link/modules/asio-standalone/asio/include/asio/impl/error_code.ipp.orig	2020-10-26 23:22:21.954194075 +0700
++++ external_libraries/link/modules/asio-standalone/asio/include/asio/impl/error_code.ipp	2020-10-26 23:25:46.716820740 +0700
+@@ -106,9 +106,14 @@
+     using namespace std;
+     strerror_r(value, buf, sizeof(buf));
+     return buf;
+-#else
++#elif defined(__GLIBC__)
+     char buf[256] = "";
+     return strerror_r(value, buf, sizeof(buf));
++#else
++    char buf[256] = "";
++    using namespace std;
++    strerror_r(value, buf, sizeof(buf));
++    return buf;
+ #endif
+ #endif // defined(ASIO_WINDOWS_DESKTOP) || defined(__CYGWIN__)
+   }

srcpkgs/supercollider/template

@@ -39,7 +39,6 @@ fi
 
 if [ "$XBPS_TARGET_LIBC" = musl ]; then
 	makedepends+=" libglob-devel"
-	broken="https://build.voidlinux.org/builders/x86_64-musl_builder/builds/31738/steps/shell_3/logs/stdio"
 fi
 
 case "$XBPS_TARGET_MACHINE" in