Create common.make with LOCAL_CFLAGS and friends

Create a common.make for definitions that are shared between tests/Makefile
and programs/Makefile, to facilitate maintenance. Start populating it with
CFLAGS/LDFLAGS variables. More to follow in subsequent commits.

Keep library/Makefile independent, at least for the time being.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/scripts/common.make b/scripts/common.make
new file mode 100644
index 0000000..cee8bd2
--- /dev/null
+++ b/scripts/common.make
@@ -0,0 +1,14 @@
+# To compile on SunOS: add "-lsocket -lnsl" to LDFLAGS
+
+CFLAGS	?= -O2
+WARNING_CFLAGS ?= -Wall -Wextra -Wformat=2 -Wno-format-nonliteral
+WARNING_CXXFLAGS ?= -Wall -Wextra -Wformat=2 -Wno-format-nonliteral
+LDFLAGS ?=
+
+LOCAL_CFLAGS = $(WARNING_CFLAGS) -I../tests/include -I../include -D_FILE_OFFSET_BITS=64
+LOCAL_CXXFLAGS = $(WARNING_CXXFLAGS) -I../include -I../tests/include -D_FILE_OFFSET_BITS=64
+LOCAL_LDFLAGS = ${MBEDTLS_TEST_OBJS} 		\
+		-L../library			\
+		-lmbedtls$(SHARED_SUFFIX)	\
+		-lmbedx509$(SHARED_SUFFIX)	\
+		-lmbedcrypto$(SHARED_SUFFIX)