mpd: request stack size on newer musl systems

since 1.1.21 musl supports reading the minimal stack size from the
PT_GNU_STACK elf header[1].

[1] https://git.musl-libc.org/cgit/musl/commit/?id=7b3348a98c139b4b4238384e52d4b0eb237e4833

srcpkgs/mpd/patches/stacksize.patch

@@ -1,17 +0,0 @@
---- src/thread/Thread.cxx	2018-02-03 20:15:41.896969703 +0100
-+++ src/thread/Thread.cxx	2018-02-03 20:17:12.640990964 +0100
-@@ -35,8 +35,12 @@
- 	if (handle == nullptr)
- 		throw MakeLastError("Failed to create thread");
- #else
--	int e = pthread_create(&handle, nullptr, ThreadProc, this);
--
-+	pthread_attr_t attr, *attrptr = nullptr;
-+	if ((pthread_attr_init(&attr) == 0)
-+	   && (pthread_attr_setstacksize(&attr, 1024*1024) == 0)) {
-+		attrptr = &attr;
-+	}
-+	int e = pthread_create(&handle, attrptr, ThreadProc, this);
- 	if (e != 0)
- 		throw MakeErrno(e, "Failed to create thread");
- #endif

srcpkgs/mpd/template

@@ -1,7 +1,7 @@
 # Template file for 'mpd'
 pkgname=mpd
 version=0.21.4
-revision=2
+revision=3
 build_style=meson
 configure_args="-Dopus=enabled -Dmikmod=enabled -Dneighbor=true
  -Dsoundcloud=enabled -Dpipe=true -Dtwolame=enabled -Dbzip2=enabled
@@ -34,6 +34,7 @@ homepage="https://www.musicpd.org/"
 changelog="https://raw.githubusercontent.com/MusicPlayerDaemon/MPD/v${version}/NEWS"
 distfiles="https://www.musicpd.org/download/mpd/${version%.*}/mpd-${version}.tar.xz"
 checksum=247112eabf1b818a4052db7f0f5917ab00831ebc60a1ec3bf1154da4dc16a5c7
+LDFLAGS+=" -Wl,-z,stack-size=1048576"
 
 system_accounts="mpd"
 mpd_homedir="/var/lib/mpd"