mysql: unbreak musl build (yours truly xtraeme)

srcpkgs/mysql/patches/musl.patch

@@ -0,0 +1,13 @@
+musl only support NPTL, so that remove that old stuff.
+
+--- mysys/stacktrace.c.orig	2015-05-08 18:43:01.661343605 +0200
++++ mysys/stacktrace.c	2015-05-08 18:43:13.669331612 +0200
+@@ -355,7 +355,7 @@ void my_print_stacktrace(uchar* stack_bo
+ #endif  /* __alpha__ */
+ 
+   /* We are 1 frame above signal frame with NPTL and 2 frames above with LT */
+-  sigreturn_frame_count = thd_lib_detected == THD_LIB_LT ? 2 : 1;
++  sigreturn_frame_count = 2;
+ 
+   while (fp < (uchar**) stack_bottom)
+   {

srcpkgs/mysql/template

@@ -1,7 +1,7 @@
 # Template file for 'mysql'
 pkgname=mysql
 version=5.6.24
-revision=1
+revision=2
 build_style=cmake
 configure_args="-DSYSCONFDIR=/etc/mysql -DMYSQL_DATADIR=/var/lib/mysql
  -DMYSQL_UNIX_ADDR=/run/mysqld/mysqld.sock -DDEFAULT_CHARSET=utf8
@@ -31,6 +31,8 @@ license="GPL-2"
 distfiles="https://downloads.skysql.com/archives/mysql-${version%.*}/mysql-${version}.tar.gz"
 checksum=37e27305b67d76883c5902dce59c89d596beee9dca7dbadd4a2e117f8101dfeb
 
+CFLAGS="-D__STDC_ISO_10646__"
+
 pre_configure() {
 	# libressl major detection.
 	sed -i '/OPENSSL_MAJOR_VERSION/s/1/2/' cmake/ssl.cmake