[libc][workflow] improve ci coverage with windows-2025 and arm ubuntu (#123745)

Add the following workflows:

- `fullbuild` on aarch64 ubuntu
- `overlay` on windows 2025
- `overlay` on aarch64 ubuntu

`ccache` variant is used on `aarch64` due to
hendrikmuhs/ccache-action#279

Author: SchrodingerZhu

.github/workflows/libc-fullbuild-tests.yml

@@ -11,12 +11,19 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-24.04
+    runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
       matrix:
         include:
-          - c_compiler: clang
+          - os: ubuntu-24.04
+            ccache-variant: sccache
+            c_compiler: clang
+            cpp_compiler: clang++
+          # TODO: remove ccache logic when https://github.com/hendrikmuhs/ccache-action/issues/279 is resolved.
+          - os: ubuntu-24.04-arm
+            ccache-variant: ccache
+            c_compiler: clang
             cpp_compiler: clang++
           # TODO: add back gcc build when it is fixed
           # - c_compiler: gcc
@@ -35,7 +42,7 @@ jobs:
       with:
         max-size: 1G
         key: libc_fullbuild_${{ matrix.c_compiler }}
-        variant: sccache
+        variant: ${{ matrix.ccache-variant }}
 
     # Notice:
     # - MPFR is required by some of the mathlib tests.
@@ -62,8 +69,8 @@ jobs:
         -DCMAKE_CXX_COMPILER=${{ matrix.cpp_compiler }}
         -DCMAKE_C_COMPILER=${{ matrix.c_compiler }}
         -DCMAKE_BUILD_TYPE=MinSizeRel
-        -DCMAKE_C_COMPILER_LAUNCHER=sccache
-        -DCMAKE_CXX_COMPILER_LAUNCHER=sccache
+        -DCMAKE_C_COMPILER_LAUNCHER=${{ matrix.ccache-variant }}
+        -DCMAKE_CXX_COMPILER_LAUNCHER=${{ matrix.ccache-variant }}
         -DCMAKE_INSTALL_PREFIX=${{ steps.strings.outputs.build-install-dir }}
         -DLLVM_ENABLE_RUNTIMES="libc;compiler-rt"
         -DLLVM_LIBC_FULL_BUILD=ON

.github/workflows/libc-overlay-tests.yml

@@ -19,14 +19,28 @@ jobs:
         include:
           # TODO: add linux gcc when it is fixed
           - os: ubuntu-24.04
+            ccache-variant: sccache
+            compiler:
+              c_compiler: clang
+              cpp_compiler: clang++
+          # TODO: remove ccache logic when https://github.com/hendrikmuhs/ccache-action/issues/279 is resolved.
+          - os: ubuntu-24.04-arm
+            ccache-variant: ccache
             compiler:
               c_compiler: clang
               cpp_compiler: clang++
           - os: windows-2022
+            ccache-variant: sccache
+            compiler:
+              c_compiler: clang-cl
+              cpp_compiler: clang-cl
+          - os: windows-2025
+            ccache-variant: sccache
             compiler:
               c_compiler: clang-cl
               cpp_compiler: clang-cl
           - os: macos-14
+            ccache-variant: sccache
             compiler:
               c_compiler: clang
               cpp_compiler: clang++
@@ -46,7 +60,7 @@ jobs:
       with:
         max-size: 1G
         key: libc_overlay_build_${{ matrix.os }}_${{ matrix.compiler.c_compiler }}
-        variant: sccache
+        variant: ${{ matrix.ccache-variant }}
 
     # MPFR is required by some of the mathlib tests.
     - name: Prepare dependencies (Ubuntu)
@@ -82,8 +96,8 @@ jobs:
         -DCMAKE_CXX_COMPILER=${{ matrix.compiler.cpp_compiler }}
         -DCMAKE_C_COMPILER=${{ matrix.compiler.c_compiler }}
         -DCMAKE_BUILD_TYPE=MinSizeRel
-        -DCMAKE_C_COMPILER_LAUNCHER=sccache
-        -DCMAKE_CXX_COMPILER_LAUNCHER=sccache
+        -DCMAKE_C_COMPILER_LAUNCHER=${{ matrix.ccache-variant }}
+        -DCMAKE_CXX_COMPILER_LAUNCHER=${{ matrix.ccache-variant }}
         -DCMAKE_POLICY_DEFAULT_CMP0141=NEW
         -DCMAKE_MSVC_DEBUG_INFORMATION_FORMAT=Embedded
         -DLLVM_ENABLE_RUNTIMES=libc