libbz2: add an io compartment

libbz2 has three parts (two of which are io).  There is a core of
in-memory compression/decompression, a stdio based file IO interface,
and a partial emulation of the gzlib interface.

Author: brooksdavis

lib/libbz2/Compartments.json

@@ -0,0 +1,23 @@
+{
+    "compartments": {
+	"io": {
+	    "symbols": [
+		"BZ2_bzWriteOpen",
+		"BZ2_bzWrite",
+		"BZ2_bzWriteClose",
+		"BZ2_bzWriteClose64",
+		"BZ2_bzReadOpen",
+		"BZ2_bzReadClose",
+		"BZ2_bzRead",
+		"BZ2_bzReadGetUnused",
+		"BZ2_bzopen",
+		"BZ2_bzdopen",
+		"BZ2_bzread",
+		"BZ2_bzwrite",
+		"BZ2_bzflush",
+		"BZ2_bzclose",
+		"BZ2_bzerror"
+            ]
+        }
+    }
+}

lib/libbz2/Makefile

@@ -4,6 +4,8 @@ BZ2DIR=	${SRCTOP}/contrib/bzip2
 
 LIB=		bz2
 SHLIB_MAJOR=	4
+COMPARTMENT_POLICY=	${.CURDIR}/Compartments.json
+
 SRCS=		bzlib.c blocksort.c compress.c crctable.c decompress.c \
 		huffman.c randtable.c
 INCS=		bzlib.h