Update clang to build LLVM to 9.0.0

This also ensure that we're using the same clang version for all our
major platforms instead of 8.0 on Linux and 7.0 on OSX/Windows.

src/ci/docker/dist-i686-linux/Dockerfile

@@ -69,7 +69,7 @@ RUN ./build-python.sh
 
 # Now build LLVM+Clang 7, afterwards configuring further compilations to use the
 # clang/clang++ compilers.
-COPY dist-x86_64-linux/build-clang.sh /tmp/
+COPY dist-x86_64-linux/build-clang.sh dist-x86_64-linux/llvm-project-centos.patch /tmp/
 RUN ./build-clang.sh
 ENV CC=clang CXX=clang++
 

src/ci/docker/dist-x86_64-linux/Dockerfile

@@ -69,7 +69,7 @@ RUN ./build-python.sh
 
 # Now build LLVM+Clang 7, afterwards configuring further compilations to use the
 # clang/clang++ compilers.
-COPY dist-x86_64-linux/build-clang.sh /tmp/
+COPY dist-x86_64-linux/build-clang.sh dist-x86_64-linux/llvm-project-centos.patch /tmp/
 RUN ./build-clang.sh
 ENV CC=clang CXX=clang++
 

src/ci/docker/dist-x86_64-linux/build-clang.sh

@@ -4,7 +4,7 @@ set -ex
 
 source shared.sh
 
-LLVM=llvmorg-8.0.0-rc2
+LLVM=llvmorg-9.0.0
 
 mkdir llvm-project
 cd llvm-project
@@ -12,6 +12,9 @@ cd llvm-project
 curl -L https://github.com/llvm/llvm-project/archive/$LLVM.tar.gz | \
   tar xzf - --strip-components=1
 
+yum install -y patch
+patch -Np1 < ../llvm-project-centos.patch
+
 mkdir clang-build
 cd clang-build
 

src/ci/docker/dist-x86_64-linux/llvm-project-centos.patch

@@ -0,0 +1,18 @@
+diff --git a/clang/lib/DirectoryWatcher/linux/DirectoryWatcher-linux.cpp b/clang/lib/DirectoryWatcher/linux/DirectoryWatcher-linux.cpp
+index 176d6d6abf3..a6d63bf24b8 100644
+--- a/clang/lib/DirectoryWatcher/linux/DirectoryWatcher-linux.cpp
++++ b/clang/lib/DirectoryWatcher/linux/DirectoryWatcher-linux.cpp
+@@ -33,6 +33,13 @@ namespace {
+ using namespace llvm;
+ using namespace clang;
+ 
++#define EPOLL_CLOEXEC -1
++#define IN_CLOEXEC -1
++#define O_CLOEXEC -1
++static int epoll_create1(int flags) { return -1; }
++static int inotify_init1(int flags) { return -1; }
++static int pipe2(int *fds, int flags) { return -1; }
++
+ /// Pipe for inter-thread synchronization - for epoll-ing on multiple
+ /// conditions. It is meant for uni-directional 1:1 signalling - specifically:
+ /// no multiple consumers, no data passing. Thread waiting for signal should

src/ci/scripts/install-clang.sh

@@ -9,10 +9,10 @@ IFS=$'\n\t'
 source "$(cd "$(dirname "$0")" && pwd)/../shared.sh"
 
 if isMacOS; then
-    curl -f "${MIRRORS_BASE}/clang%2Bllvm-7.0.0-x86_64-apple-darwin.tar.xz" | tar xJf -
+    curl -f "${MIRRORS_BASE}/clang%2Bllvm-9.0.0-x86_64-darwin-apple.tar.xz" | tar xJf -
 
-    ciCommandSetEnv CC "$(pwd)/clang+llvm-7.0.0-x86_64-apple-darwin/bin/clang"
-    ciCommandSetEnv CXX "$(pwd)/clang+llvm-7.0.0-x86_64-apple-darwin/bin/clang++"
+    ciCommandSetEnv CC "$(pwd)/clang+llvm-9.0.0-x86_64-darwin-apple/bin/clang"
+    ciCommandSetEnv CXX "$(pwd)/clang+llvm-9.0.0-x86_64-darwin-apple/bin/clang++"
 
     # Configure `AR` specifically so rustbuild doesn't try to infer it as
     # `clang-ar` by accident.
@@ -27,17 +27,18 @@ elif isWindows && [[ -z ${MINGW_URL+x} ]]; then
     # Note that the LLVM installer is an NSIS installer
     #
     # Original downloaded here came from
-    # http://releases.llvm.org/7.0.0/LLVM-7.0.0-win64.exe
-    # That installer was run through `wine` on Linux and then the resulting
-    # installation directory (found in `$HOME/.wine/drive_c/Program Files/LLVM`) was
-    # packaged up into a tarball. We've had issues otherwise that the installer will
-    # randomly hang, provide not a lot of useful information, pollute global state,
-    # etc. In general the tarball is just more confined and easier to deal with when
-    # working with various CI environments.
+    # http://releases.llvm.org/9.0.0/LLVM-9.0.0-win64.exe
+    # That installer was run through `wine ./installer.exe /S /NCRC` on Linux
+    # and then the resulting installation directory (found in
+    # `$HOME/.wine/drive_c/Program Files/LLVM`) was packaged up into a tarball.
+    # We've had issues otherwise that the installer will randomly hang, provide
+    # not a lot of useful information, pollute global state, etc. In general the
+    # tarball is just more confined and easier to deal with when working with
+    # various CI environments.
 
     mkdir -p citools
     cd citools
-    curl -f "${MIRRORS_BASE}/LLVM-7.0.0-win64.tar.gz" | tar xzf -
+    curl -f "${MIRRORS_BASE}/LLVM-9.0.0-win64.tar.gz" | tar xzf -
     ciCommandSetEnv RUST_CONFIGURE_ARGS \
         "${RUST_CONFIGURE_ARGS} --set llvm.clang-cl=$(pwd)/clang-rust/bin/clang-cl.exe"
 fi