[workflows] LLVM release_13x CI changes

Changes to LLVM release_13x to allow it to be built by GitHub.

This is a combination of 4 commits by Abraham Tover from the release_13x branch
which had duplicate commit messages and overlapping content:

    c53d8f8 LLVM release_13x CI changes
    83c659a Fix release_13x CI dockerfile
    5e6e4cb Fix release_13x CI dockerfile
    fc42794 LLVM release_13x CI changes

.github/workflows/Ubuntu20Dockerfile

@@ -34,6 +34,14 @@ RUN apt-get install -y software-properties-common && \
     apt-get install -f -y llvm-10 clang-10 && \
     apt-get install -f -y llvm-11 clang-11
 
+# Install the tools for release_13x
+RUN apt install -y build-essential manpages-dev \
+    libssl-dev zlib1g-dev \
+    libbz2-dev libreadline-dev libsqlite3-dev libncurses5-dev \
+    libncursesw5-dev xz-utils tk-dev libffi-dev liblzma-dev python-openssl && \
+    add-apt-repository ppa:ubuntu-toolchain-r/test && \
+    apt install -y gcc-11 g++-11 python python3-distutils
+
 RUN cd /opt && \
     wget https://github.com/Kitware/CMake/releases/download/v3.20.0/cmake-3.20.0-linux-aarch64.sh && \
     /bin/sh cmake-3.20.0-linux-aarch64.sh --skip-license --include-subdir && \
@@ -44,7 +52,7 @@ RUN ln -s /usr/bin/ninja-build /usr/local/bin/ninja
 RUN mkdir /home/github/
 
 RUN mkdir /home/root && cd home/root && \
-    git clone --depth 1 --single-branch --branch release_12x https://github.com/flang-compiler/classic-flang-llvm-project.git classic-flang-llvm-project && \
+    git clone --depth 1 --single-branch --branch release_13x https://github.com/flang-compiler/classic-flang-llvm-project.git classic-flang-llvm-project && \
     cd classic-flang-llvm-project && \
     ./build-llvm-project.sh -t AArch64 -p /home/github/usr/local -n `nproc --ignore=1` -a /usr/bin/gcc-10 -b /usr/bin/g++-10 -i
 

.github/workflows/build_push_docker_image_Ubuntu20.yml

@@ -3,7 +3,7 @@ name: Pre-compile llvm ARM64
 on:
   workflow_dispatch:
   push:
-    branches: [ release_11x, release_12x ]
+    branches: [ release_11x, release_12x, release_13x ]
     paths-include:
       - '**/.github/workflows/build_push_docker_image_Ubuntu20.yml'
       - '**/.github/workflows/Ubuntu20Dockerfile.yml'

.github/workflows/flang-tests.yml

@@ -2,7 +2,7 @@ name: Build and test Flang
 
 on:
   pull_request:
-    branches: [ release_100, release_11x, release_12x ]
+    branches: [ release_100, release_11x, release_12x, release_13x ]
 
 jobs:
   build:

.github/workflows/pre-compile_llvm.yml

@@ -3,7 +3,7 @@ name: Pre-compile llvm
 on:
   workflow_dispatch:
   push:
-    branches: [ release_100, release_11x, release_12x ]
+    branches: [ release_100, release_11x, release_12x, release_13x ]
 
 jobs:
   build:

build-llvm-project.sh

@@ -52,7 +52,8 @@ CMAKE_OPTIONS="-DCMAKE_INSTALL_PREFIX=$INSTALL_PREFIX \
     -DCMAKE_C_COMPILER=$C_COMPILER_PATH \
     -DCMAKE_CXX_COMPILER=$CXX_COMPILER_PATH \
     -DLLVM_TARGETS_TO_BUILD=$TARGET \
-    -DLLVM_ENABLE_CLASSIC_FLANG=ON"
+    -DLLVM_ENABLE_CLASSIC_FLANG=ON \
+    -DFLANG_BUILD_NEW_DRIVER=OFF"
 # Warning: the -DLLVM_ENABLE_PROJECTS option is specified with cmake
 # to avoid issues with nested quotation marks