Update clang from 13 to 17 (#30)

Use clang-17.  clang-format-17 produces sligtly different output from clang-format-13, so there is an annoying cost using clang-13 for circt CI.

circt-ci-build/Dockerfile

@@ -16,24 +16,18 @@ RUN pip3 install yapf toml GitPython
 # Install a more recent release of LLVM
 RUN wget https://apt.llvm.org/llvm.sh; \
   chmod +x llvm.sh; \
-  ./llvm.sh 13;\
-  apt install -y clang-format-13 clang-tidy-13
-
-RUN ln -s /usr/bin/clang-13 /usr/bin/clang; \
-  ln -s /usr/bin/clang++-13 /usr/bin/clang++; \
-  ln -s /usr/bin/clang-tidy-13 /usr/bin/clang-tidy; \
-  ln -s /usr/bin/clang-tidy-diff-13.py /usr/bin/clang-tidy-diff; \
-  ln -s /usr/bin/clang-format-13 /usr/bin/clang-format; \
-  ln -s /usr/bin/clang-format-diff-13 /usr/bin/clang-format-diff; \
-  ln -s /usr/bin/git-clang-format-13 /usr/bin/git-clang-format; \
-  ln -s /usr/bin/lld-13 /usr/bin/lld; \
-  ln -s /usr/bin/lld-13 /usr/bin/ld.lld
-
-# Install clang-16, required for slang builds
-RUN wget https://apt.llvm.org/llvm.sh; \
-  chmod +x llvm.sh; \
-  ./llvm.sh 16;\
-  apt install -y clang-16
+  ./llvm.sh 17;\
+  apt install -y clang-format-17 clang-tidy-17
+
+RUN ln -s /usr/bin/clang-17 /usr/bin/clang; \
+  ln -s /usr/bin/clang++-17 /usr/bin/clang++; \
+  ln -s /usr/bin/clang-tidy-17 /usr/bin/clang-tidy; \
+  ln -s /usr/bin/clang-tidy-diff-17.py /usr/bin/clang-tidy-diff; \
+  ln -s /usr/bin/clang-format-17 /usr/bin/clang-format; \
+  ln -s /usr/bin/clang-format-diff-17 /usr/bin/clang-format-diff; \
+  ln -s /usr/bin/git-clang-format-17 /usr/bin/git-clang-format; \
+  ln -s /usr/bin/lld-17 /usr/bin/lld; \
+  ln -s /usr/bin/lld-17 /usr/bin/ld.lld
 
 # Install GCC 11 to get C++20 header support and support for building slang
 RUN add-apt-repository ppa:ubuntu-toolchain-r/test