G M:  Remove unneeded warnings in buildit that are hindering porting.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@192012 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/buildit b/lib/buildit
index aa4f10e..af6b466 100755
--- a/lib/buildit
+++ b/lib/buildit
@@ -36,8 +36,7 @@
 fi
 
 EXTRA_FLAGS="-nostdinc++ -std=c++11 -fstrict-aliasing -Wall -Wextra -Wshadow -Wconversion \
-             -Wnewline-eof -Wpadded -Wmissing-prototypes -Wstrict-aliasing=2 \
-             -Wstrict-overflow=4 "
+             -Wpadded -Wstrict-aliasing=2 -Wstrict-overflow=4 "
 
 case $TRIPLE in
   *-apple-*)