[clang] [clang][Darwin] Simply deployment version assignment in the Driver (PR #142013)

[Cyndy Ishida via cfe-commits]

================
@@ -2313,12 +2340,12 @@ void Darwin::AddDeploymentTarget(DerivedArgList &Args) const {
   SDKInfo = parseSDKSettings(getVFS(), Args, getDriver());
 
   // The OS and the version can be specified using the -target argument.
-  std::optional<DarwinPlatform> OSTarget =
+  std::optional<DarwinPlatform> DP =
----------------
cyndyishida wrote:

I can change it to `PlatformForDarwin`

https://github.com/llvm/llvm-project/pull/142013