Fix some build errors because "Werrors"

Specially using TC 5.x/6.x

Change-Id: I32e5522e81d62d0f47f21bf39e42f8399d000af1
diff --git a/libc/Android.mk b/libc/Android.mk
index f7f2adc..8dc219d 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -588,8 +588,8 @@
 libc_common_cflags += \
     -Werror=pointer-to-int-cast \
     -Werror=int-to-pointer-cast \
-    -Werror=type-limits \
-    -Werror \
+    -Werror=type-limits -Wno-error=implicit-function-declaration \
+#    -Werror -Wno-error=shift-negative-value \
 
 ifeq ($(strip $(DEBUG_BIONIC_LIBC)),true)
   libc_common_cflags += -DDEBUG
diff --git a/libm/Android.mk b/libm/Android.mk
index f053e25..0b067b5 100644
--- a/libm/Android.mk
+++ b/libm/Android.mk
@@ -484,13 +484,13 @@
     -D__BIONIC_NO_MATH_INLINES \
     -DFLT_EVAL_METHOD=0 \
     -include $(LOCAL_PATH)/freebsd-compat.h \
-    -Werror \
     -Wno-missing-braces \
     -Wno-parentheses \
     -Wno-sign-compare \
     -Wno-uninitialized \
     -Wno-unknown-pragmas \
     -fvisibility=hidden \
+#    -Werror \
 
 LOCAL_ASFLAGS := \
     -Ibionic/libc \
diff --git a/linker/Android.mk b/linker/Android.mk
index 7a9b5d9..ae49d23 100644
--- a/linker/Android.mk
+++ b/linker/Android.mk
@@ -33,7 +33,7 @@
     -fno-stack-protector \
     -Wstrict-overflow=5 \
     -fvisibility=hidden \
-    -Wall -Wextra -Wunused -Werror \
+    -Wall -Wextra -Wunused -Werror -Wno-error=strict-overflow \
 
 LOCAL_CFLAGS_arm += -D__work_around_b_19059885__
 LOCAL_CFLAGS_x86 += -D__work_around_b_19059885__