Merge bitcoin/bitcoin#25028: ci: Clone iwyu only if missing

fa847ed ci: Clone iwyu only if missing (MacroFake)

Pull request description:

  This doesn't change anything for Cirrus CI, but makes it easier to play locally.

  For reference, the same check is done when cloning `DIR_FUZZ_IN`.

ACKs for top commit:
  fanquake:
    ACK fa847ed

Tree-SHA512: 3d9689ea85b2380dcf83d26997c89c63f163aebfae9530180cb2420872a9f30d7b3dc59722e2e49684fdb3e30859b1e08e1272f6d083c07f213e9f5a190ca21f

Author: fanquake

ci/test/04_install.sh

@@ -112,10 +112,13 @@ if [[ ${USE_MEMORY_SANITIZER} == "true" ]]; then
 fi
 
 if [[ "${RUN_TIDY}" == "true" ]]; then
-  CI_EXEC "mkdir -p ${BASE_SCRATCH_DIR}/iwyu/build/"
-  CI_EXEC "git clone --depth=1 https://github.com/include-what-you-use/include-what-you-use -b clang_14 ${BASE_SCRATCH_DIR}/iwyu/include-what-you-use"
-  CI_EXEC "cd ${BASE_SCRATCH_DIR}/iwyu/build && cmake -G 'Unix Makefiles' -DCMAKE_PREFIX_PATH=/usr/lib/llvm-14 ../include-what-you-use"
-  CI_EXEC "cd ${BASE_SCRATCH_DIR}/iwyu/build && make install $MAKEJOBS"
+  export DIR_IWYU="${BASE_SCRATCH_DIR}/iwyu"
+  if [ ! -d "${DIR_IWYU}" ]; then
+    CI_EXEC "mkdir -p ${DIR_IWYU}/build/"
+    CI_EXEC "git clone --depth=1 https://github.com/include-what-you-use/include-what-you-use -b clang_14 ${DIR_IWYU}/include-what-you-use"
+    CI_EXEC "cd ${DIR_IWYU}/build && cmake -G 'Unix Makefiles' -DCMAKE_PREFIX_PATH=/usr/lib/llvm-14 ../include-what-you-use"
+    CI_EXEC "cd ${DIR_IWYU}/build && make install $MAKEJOBS"
+  fi
 fi
 
 if [ -z "$DANGER_RUN_CI_ON_HOST" ]; then

ci/test/06_script_b.sh

@@ -38,7 +38,7 @@ if [ "${RUN_TIDY}" = "true" ]; then
   export P_CI_DIR="${BASE_BUILD_DIR}/bitcoin-$HOST/src/"
   CI_EXEC run-clang-tidy "${MAKEJOBS}"
   export P_CI_DIR="${BASE_BUILD_DIR}/bitcoin-$HOST/"
-  CI_EXEC "python3 ${BASE_SCRATCH_DIR}/iwyu/include-what-you-use/iwyu_tool.py"\
+  CI_EXEC "python3 ${DIR_IWYU}/include-what-you-use/iwyu_tool.py"\
           " src/compat"\
           " src/init"\
           " src/rpc/signmessage.cpp"\