PVF worker: Maintain lists of used syscalls (#1663)

Co-authored-by: Mira Ressel <mira@parity.io>

.cargo/musl-gcc

@@ -0,0 +1,13 @@
+#!/bin/sh
+
+# Wrapper for building with musl.
+#
+# musl unfortunately requires a musl-enabled C compiler (musl-gcc) to be
+# installed, which can be kind of a pain to get installed depending on the
+# distro. That's not a very good user experience.
+#
+# The real musl-gcc wrapper sets the correct system include paths for linking
+# with musl libc library. Since this is not actually used to link any binaries
+# it should most likely work just fine.
+
+gcc "$@"