ida: Start new test_ida module

Start transitioning the IDA tests into kernel space.  Framework heavily
cribbed from test_xarray.c.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
diff --git a/lib/Makefile b/lib/Makefile
index 90dc552..18d87ca 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -50,6 +50,7 @@
 obj-$(CONFIG_TEST_FIRMWARE) += test_firmware.o
 obj-$(CONFIG_TEST_SYSCTL) += test_sysctl.o
 obj-$(CONFIG_TEST_HASH) += test_hash.o test_siphash.o
+obj-$(CONFIG_TEST_IDA) += test_ida.o
 obj-$(CONFIG_TEST_KASAN) += test_kasan.o
 CFLAGS_test_kasan.o += -fno-builtin
 obj-$(CONFIG_TEST_UBSAN) += test_ubsan.o