Link RS compatibility files with libc and make bcc_compat a regular dep.

If we don't do "-lc", we end up missing symbols like "memset" on our non-NEON
builds. It also makes more sense to have bcc_compat as a standard dependency
for now, since it occasionally changes the way we compile/link our source
files.

Change-Id: I4b0ead66caa7c72fb7733db8804a33faa5350930
diff --git a/core/definitions.mk b/core/definitions.mk
index 2cf5283..7bee582 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -833,7 +833,7 @@
 	$(RS_PREBUILT_COMPILER_RT) \
 	-o $@ -L prebuilts/gcc/ \
 	-L $(TARGET_OUT_INTERMEDIATE_LIBRARIES) $(RS_PREBUILT_LIBPATH) \
-	-lRSSupport -lm
+	-lRSSupport -lm -lc
 endef
 
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