GH-131296: Fix clang-cl warnings on Windows in sqlite3 (GH-131906)

Author: chris-eibl

PCbuild/sqlite3.vcxproj

@@ -100,6 +100,7 @@
       <AdditionalIncludeDirectories>$(sqlite3Dir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <PreprocessorDefinitions>SQLITE_ENABLE_MATH_FUNCTIONS;SQLITE_ENABLE_FTS4;SQLITE_ENABLE_FTS5;SQLITE_ENABLE_RTREE;SQLITE_OMIT_AUTOINIT;SQLITE_API=__declspec(dllexport);%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <WarningLevel>Level1</WarningLevel>
+      <AdditionalOptions Condition="$(PlatformToolset) == 'ClangCL'">%(AdditionalOptions) -Wno-unused</AdditionalOptions>
     </ClCompile>
     <ResourceCompile>
       <PreprocessorDefinitions>SQLITE_VERSION=$(SqliteVersion);SQLITE_MAJOR_VERSION=$(SqliteMajorVersion);SQLITE_MINOR_VERSION=$(SqliteMinorVersion);SQLITE_MICRO_VERSION=$(SqliteMicroVersion);SQLITE_PATCH_VERSION=$(SqlitePatchVersion);%(PreprocessorDefinitions)</PreprocessorDefinitions>