compiler_rt: Import popcountdi2.c and popcountsi2.c files

Imported from the LLVM compiler_rt library on master branch as of
30 Oct 2018 (SVN revision: r345645).

This is to get the __popcountsi2(si_int a) and __popcountdi2(di_int a)
builtin which are required by a driver that uses a __builtin_popcount().

Change-Id: I8e0d97cebdd90d224690c8ce1b02e657acdddb25
Signed-off-by: Lionel Debieve <lionel.debieve@st.com>
diff --git a/lib/compiler-rt/compiler-rt.mk b/lib/compiler-rt/compiler-rt.mk
index 1ffc9d6..40c669f 100644
--- a/lib/compiler-rt/compiler-rt.mk
+++ b/lib/compiler-rt/compiler-rt.mk
@@ -28,8 +28,11 @@
 # POSSIBILITY OF SUCH DAMAGE.
 #
 
+COMPILER_RT_SRCS	:=	lib/compiler-rt/builtins/popcountdi2.c		\
+				lib/compiler-rt/builtins/popcountsi2.c
+
 ifeq (${ARCH},aarch32)
-COMPILER_RT_SRCS	:=	lib/compiler-rt/builtins/arm/aeabi_ldivmod.S	\
+COMPILER_RT_SRCS	+=	lib/compiler-rt/builtins/arm/aeabi_ldivmod.S	\
 				lib/compiler-rt/builtins/arm/aeabi_uldivmod.S	\
 				lib/compiler-rt/builtins/ctzdi2.c		\
 				lib/compiler-rt/builtins/divdi3.c		\