[lldb] Narrow scope of -Wno-deprecated-declarations (NFC) (#112276)

Currently all of LLDB is being compiled with
-Wno-deprecated-declarations. That's not desirable, especially as part
of the LLVM monorepo, as we miss deprecation warnings from LLVM and
clang.

According to the git history, this was first introduced to suppress
warnings related to auto_ptr. Since then, other things have been
deprecated and gone unnoticed. This patch limits the flag to Host.mm
which uses a handful of LSApplication headers that have no replacement.

rdar://112040718

lldb/cmake/modules/LLDBConfig.cmake

@@ -188,7 +188,6 @@ include_directories("${CMAKE_CURRENT_BINARY_DIR}/../clang/include")
 
 if (LLVM_COMPILER_IS_GCC_COMPATIBLE)
   # Disable GCC warnings
-  append("-Wno-deprecated-declarations" CMAKE_CXX_FLAGS)
   append("-Wno-unknown-pragmas" CMAKE_CXX_FLAGS)
   append("-Wno-strict-aliasing" CMAKE_CXX_FLAGS)
 
@@ -198,7 +197,6 @@ endif()
 
 # Disable Clang warnings
 if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
-  append("-Wno-deprecated-register" CMAKE_CXX_FLAGS)
   append("-Wno-vla-extension" CMAKE_CXX_FLAGS)
 endif()
 

lldb/source/Host/macosx/objcxx/CMakeLists.txt

@@ -16,4 +16,6 @@ add_lldb_library(lldbHostMacOSXObjCXX NO_PLUGIN_DEPENDENCIES
     TargetParser
   )
 
-target_compile_options(lldbHostMacOSXObjCXX PRIVATE -fno-objc-exceptions)
+target_compile_options(lldbHostMacOSXObjCXX PRIVATE
+  -fno-objc-exceptions
+  -Wno-deprecated-declarations)