Switch to LOCAL_SRC_FILES_EXCLUDE

This moves the generic arm/arm64/x86 settings into the main makefiles
and makes the rest of them derivatives. This better aligns with how
soong handles arch/cpu variants.

Also updates the Android.bp to make it consistent with the make
versions.

Change-Id: I5a0275d992bc657459eb6fe1697ad2336731d122
diff --git a/libc/arch-x86/atom/atom.mk b/libc/arch-x86/atom/atom.mk
index 3f28fb2..1afabac 100644
--- a/libc/arch-x86/atom/atom.mk
+++ b/libc/arch-x86/atom/atom.mk
@@ -1,32 +1,27 @@
 libc_bionic_src_files_x86 += \
     arch-x86/atom/string/sse2-bzero-atom.S \
-    arch-x86/atom/string/sse2-memchr-atom.S \
-    arch-x86/atom/string/sse2-memrchr-atom.S \
     arch-x86/atom/string/sse2-memset-atom.S \
-    arch-x86/atom/string/sse2-strchr-atom.S \
     arch-x86/atom/string/sse2-strlen-atom.S \
-    arch-x86/atom/string/sse2-strnlen-atom.S \
-    arch-x86/atom/string/sse2-strrchr-atom.S \
-    arch-x86/atom/string/sse2-wcschr-atom.S \
-    arch-x86/atom/string/sse2-wcsrchr-atom.S \
-    arch-x86/atom/string/sse2-wcslen-atom.S \
-    arch-x86/atom/string/sse2-wcscmp-atom.S \
     arch-x86/atom/string/ssse3-bcopy-atom.S \
     arch-x86/atom/string/ssse3-memcmp-atom.S \
     arch-x86/atom/string/ssse3-memcpy-atom.S \
     arch-x86/atom/string/ssse3-memmove-atom.S \
-    arch-x86/atom/string/ssse3-strcat-atom.S \
-    arch-x86/atom/string/ssse3-strcmp-atom.S \
     arch-x86/atom/string/ssse3-strcpy-atom.S \
-    arch-x86/atom/string/ssse3-strlcat-atom.S \
-    arch-x86/atom/string/ssse3-strlcpy-atom.S \
-    arch-x86/atom/string/ssse3-strncat-atom.S \
-    arch-x86/atom/string/ssse3-strncmp-atom.S \
     arch-x86/atom/string/ssse3-strncpy-atom.S \
-    arch-x86/atom/string/ssse3-wcscat-atom.S \
-    arch-x86/atom/string/ssse3-wcscpy-atom.S \
     arch-x86/atom/string/ssse3-wmemcmp-atom.S
 
-libc_bionic_src_files_x86 += \
-    arch-x86/silvermont/string/sse2-stpcpy-slm.S \
-    arch-x86/silvermont/string/sse2-stpncpy-slm.S
+libc_bionic_src_files_exclude_x86 += \
+    arch-x86/generic/string/memcmp.S \
+
+libc_bionic_src_files_exclude_x86 += \
+    arch-x86/silvermont/string/sse2-bcopy-slm.S \
+    arch-x86/silvermont/string/sse2-bzero-slm.S \
+    arch-x86/silvermont/string/sse2-memcpy-slm.S \
+    arch-x86/silvermont/string/sse2-memmove-slm.S \
+    arch-x86/silvermont/string/sse2-memset-slm.S \
+    arch-x86/silvermont/string/sse2-strcpy-slm.S \
+    arch-x86/silvermont/string/sse2-strlen-slm.S \
+    arch-x86/silvermont/string/sse2-strncpy-slm.S \
+
+libc_freebsd_src_files_exclude_x86 += \
+    upstream-freebsd/lib/libc/string/wmemcmp.c \