Add config option to use dlmalloc instead of mheap

Configure w/ --enable-dlmalloc, see .../build-data/platforms/vpp.mk

src/vppinfra/dlmalloc.[ch] are slightly modified versions of the
well-known Doug Lea malloc. Main advantage: dlmalloc mspaces have no
inherent size limit.

Change-Id: I19b3f43f3c65bcfb82c1a265a97922d01912446e
Signed-off-by: Dave Barach <dave@barachs.net>
diff --git a/src/vpp-api/vapi/Makefile.am b/src/vpp-api/vapi/Makefile.am
index 07ef46e..e1bd813 100644
--- a/src/vpp-api/vapi/Makefile.am
+++ b/src/vpp-api/vapi/Makefile.am
@@ -15,7 +15,7 @@
 ACLOCAL_AMFLAGS = -I m4
 AM_LIBTOOLFLAGS = --quiet
 
-AM_CFLAGS = @CPU_FLAGS@ -Wall -I${top_srcdir} -I${top_builddir} -I. -I$(top_srcdir)/vpp-api/
+AM_CFLAGS = @CPU_FLAGS@ @DLMALLOC@ -Wall -I${top_srcdir} -I${top_builddir} -I. -I$(top_srcdir)/vpp-api/
 
 AM_LDFLAGS = -shared -avoid-version -rpath /none -no-undefined