[llvm] [CI][NFC] Fix shellcheck warnings in CI scripts (PR #86877)

[Marc Auberer via llvm-commits]

https://github.com/marcauberer created https://github.com/llvm/llvm-project/pull/86877

This fixes all shellcheck warnings we have in `monolithic-linux.sh` and `monolithic-windows.sh`.
All of them have to do with [SC2086](https://www.shellcheck.net/wiki/SC2086) - Double quote to prevent globbing and word splitting.

>From 818515bffbf482480ddcdd45da18f26407dce23c Mon Sep 17 00:00:00 2001
From: Marc Auberer <marc.auberer at chillibits.com>
Date: Wed, 27 Mar 2024 22:43:20 +0100
Subject: [PATCH] [CI][NFC] Fix shellcheck warnings in CI scripts

---
 .ci/monolithic-linux.sh   | 8 ++++----
 .ci/monolithic-windows.sh | 8 ++++----
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/.ci/monolithic-linux.sh b/.ci/monolithic-linux.sh
index 9e670c447fbadd..35f1aacb4985f0 100755
--- a/.ci/monolithic-linux.sh
+++ b/.ci/monolithic-linux.sh
@@ -18,7 +18,7 @@ set -o pipefail
 
 MONOREPO_ROOT="${MONOREPO_ROOT:="$(git rev-parse --show-toplevel)"}"
 BUILD_DIR="${BUILD_DIR:=${MONOREPO_ROOT}/build}"
-rm -rf ${BUILD_DIR}
+rm -rf "${BUILD_DIR}"
 
 ccache --zero-stats
 
@@ -37,8 +37,8 @@ projects="${1}"
 targets="${2}"
 
 echo "--- cmake"
-pip install -q -r ${MONOREPO_ROOT}/mlir/python/requirements.txt
-cmake -S ${MONOREPO_ROOT}/llvm -B ${BUILD_DIR} \
+pip install -q -r "${MONOREPO_ROOT}"/mlir/python/requirements.txt
+cmake -S "${MONOREPO_ROOT}"/llvm -B "${BUILD_DIR}" \
       -D LLVM_ENABLE_PROJECTS="${projects}" \
       -G Ninja \
       -D CMAKE_BUILD_TYPE=Release \
@@ -54,4 +54,4 @@ cmake -S ${MONOREPO_ROOT}/llvm -B ${BUILD_DIR} \
 
 echo "--- ninja"
 # Targets are not escaped as they are passed as separate arguments.
-ninja -C "${BUILD_DIR}" -k 0 ${targets}
+ninja -C "${BUILD_DIR}" -k 0 "${targets}"
diff --git a/.ci/monolithic-windows.sh b/.ci/monolithic-windows.sh
index 52ba13036f9159..f84c0966704e73 100755
--- a/.ci/monolithic-windows.sh
+++ b/.ci/monolithic-windows.sh
@@ -19,7 +19,7 @@ set -o pipefail
 MONOREPO_ROOT="${MONOREPO_ROOT:="$(git rev-parse --show-toplevel)"}"
 BUILD_DIR="${BUILD_DIR:=${MONOREPO_ROOT}/build}"
 
-rm -rf ${BUILD_DIR}
+rm -rf "${BUILD_DIR}"
 
 if [[ -n "${CLEAR_CACHE:-}" ]]; then
   echo "clearing sccache"
@@ -37,14 +37,14 @@ projects="${1}"
 targets="${2}"
 
 echo "--- cmake"
-pip install -q -r ${MONOREPO_ROOT}/mlir/python/requirements.txt
+pip install -q -r "${MONOREPO_ROOT}"/mlir/python/requirements.txt
 
 # The CMAKE_*_LINKER_FLAGS to disable the manifest come from research
 # on fixing a build reliability issue on the build server, please
 # see https://github.com/llvm/llvm-project/pull/82393 and
 # https://discourse.llvm.org/t/rfc-future-of-windows-pre-commit-ci/76840/40
 # for further information.
-cmake -S ${MONOREPO_ROOT}/llvm -B ${BUILD_DIR} \
+cmake -S "${MONOREPO_ROOT}"/llvm -B "${BUILD_DIR}" \
       -D LLVM_ENABLE_PROJECTS="${projects}" \
       -G Ninja \
       -D CMAKE_BUILD_TYPE=Release \
@@ -62,4 +62,4 @@ cmake -S ${MONOREPO_ROOT}/llvm -B ${BUILD_DIR} \
 
 echo "--- ninja"
 # Targets are not escaped as they are passed as separate arguments.
-ninja -C "${BUILD_DIR}" -k 0 ${targets}
+ninja -C "${BUILD_DIR}" -k 0 "${targets}"