Fix compat build without tests and deduplicate BuildRequires

1. Set LLVM_INCLUDE_TESTS:BOOL=OFF in order to build clang without
   requiring googletest as we do not run the tests anyway.

2. Backport a patch from upstream that fixes the generation
   of *.exports.

3. Deduplicate a few BuildRequires entries.

0001-clang-set-python3-as-required-build-dependency.patch

@@ -0,0 +1,39 @@
+From 96962d5512fbc6af0ada0f13e6be332c026529cb Mon Sep 17 00:00:00 2001
+From: Petr Hosek <phosek@google.com>
+Date: Fri, 9 Jun 2023 07:51:40 +0000
+Subject: [PATCH] [clang] set python3 as required build dependency
+
+The required HTMLLogger include file needs python3 to run
+resource_bundle.py to bundle all the html/css/js resources. However, if
+user sets -DLLVM_INCLUDE_TESTS=OFF, CMake will not find python3 and the
+resource bundler will never be executed. This patch set the python3 as a
+required build dependency to fix this problem.
+
+Patch By: Avimitin
+
+Differential Revision: https://reviews.llvm.org/D152418
+---
+ clang/CMakeLists.txt | 6 +++---
+ 1 file changed, 3 insertions(+), 3 deletions(-)
+
+diff --git a/clang/CMakeLists.txt b/clang/CMakeLists.txt
+index 8220a9dbfd4d..f7936d72e088 100644
+--- a/clang/CMakeLists.txt
++++ b/clang/CMakeLists.txt
+@@ -82,10 +82,10 @@ if(CLANG_BUILT_STANDALONE)
+   set( CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib${LLVM_LIBDIR_SUFFIX} )
+   set( CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib${LLVM_LIBDIR_SUFFIX} )
+ 
+-  if(LLVM_INCLUDE_TESTS)
+-    find_package(Python3 ${LLVM_MINIMUM_PYTHON_VERSION} REQUIRED
+-      COMPONENTS Interpreter)
++  find_package(Python3 ${LLVM_MINIMUM_PYTHON_VERSION} REQUIRED
++    COMPONENTS Interpreter)
+ 
++  if(LLVM_INCLUDE_TESTS)
+     # Check prebuilt llvm/utils.
+     if(EXISTS ${LLVM_TOOLS_BINARY_DIR}/FileCheck${CMAKE_EXECUTABLE_SUFFIX}
+         AND EXISTS ${LLVM_TOOLS_BINARY_DIR}/count${CMAKE_EXECUTABLE_SUFFIX}
+-- 
+2.41.0
+

clang.spec

@@ -73,6 +73,9 @@ Patch7:     D141581.diff
 # See https://reviews.llvm.org/D138472
 Patch8:     D138472.diff
 
+# Backport from LLVM 18.
+Patch9:     0001-clang-set-python3-as-required-build-dependency.patch
+
 Patch10:    fix-ieee128-cross.diff
 
 # https://reviews.llvm.org/D155192
@@ -91,20 +94,21 @@ Patch201:   0001-clang-tools-extra-Make-test-dependency-on-LLVMHello-.patch
 BuildRequires:	clang
 BuildRequires:	cmake
 BuildRequires:	ninja-build
+
 %if %{with compat_build}
-BuildRequires:	llvm%{maj_ver}-devel = %{version}
-BuildRequires:	llvm%{maj_ver}-static = %{version}
-BuildRequires:	llvm%{maj_ver}-cmake-utils = %{version}
+%global llvm_pkg_name llvm%{maj_ver}
 %else
-BuildRequires:	llvm-devel = %{version}
-BuildRequires:	llvm-cmake-utils = %{version}
+%global llvm_pkg_name llvm
 BuildRequires:  llvm-test = %{version}
-# llvm-static is required, because clang-tablegen needs libLLVMTableGen, which
-# is not included in libLLVM.so.
-BuildRequires:	llvm-static = %{version}
 BuildRequires:  llvm-googletest = %{version}
 %endif
 
+BuildRequires:	%{llvm_pkg_name}-devel = %{version}
+# llvm-static is required, because clang-tablegen needs libLLVMTableGen, which
+# is not included in libLLVM.so.
+BuildRequires:	%{llvm_pkg_name}-static = %{version}
+BuildRequires:	%{llvm_pkg_name}-cmake-utils = %{version}
+
 BuildRequires:	libxml2-devel
 BuildRequires:	perl-generators
 BuildRequires:	ncurses-devel
@@ -348,6 +352,7 @@ sed -i 's/\@FEDORA_LLVM_LIB_SUFFIX\@//g' test/lit.cfg.py
 	-DCLANG_BUILD_TOOLS:BOOL=OFF \
 	-DCMAKE_INSTALL_PREFIX=%{install_prefix} \
 	-DCLANG_INCLUDE_TESTS:BOOL=OFF \
+	-DLLVM_INCLUDE_TESTS:BOOL=OFF \
 	-DLLVM_CMAKE_DIR=%{install_libdir}/cmake/llvm \
 %else
 	-DCLANG_INCLUDE_TESTS:BOOL=ON \