crash: twiddle include path for musl.

srcpkgs/crash/template

@@ -1,7 +1,7 @@
 # Template file for 'crash'
 pkgname=crash
 version=7.1.0
-revision=3
+revision=4
 build_style=gnu-makefile
 hostmakedepends="flex"
 makedepends="ncurses-devel zlib-devel lzo-devel"
@@ -18,12 +18,13 @@ post_extract() {
 	sed -i 's|/usr/lib/debug/lib/modules|/usr/lib/debug/usr/lib/modules|g' defs.h
 	sed -i 's|/boot/efi/redhat|/usr/lib/debug/boot/|g' filesys.c
 }
-
 do_build() {
+	make gdb_unzip
+	sed -i 's|sys/debugreg.h|asm/debugreg.h|g' gdb-7.6/gdb/amd64-linux-nat.c
+
 	make ${makejobs} lzo
 	make ${makejobs} extensions
 }
-
 do_install() {
 	vbin crash
 	vman crash.8