[clang] Optimize Cache Insertion with try_emplace for Reduced Lookups (PR #131402)

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<!--LLVM CODE FORMAT COMMENT: {clang-format}-->


:warning: C/C++ code formatter, clang-format found issues in your code. :warning:

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``````````bash
git-clang-format --diff fbf0276b6a7a7a4508c373cf87fc349569652659 28f6d8b6677e32f45f5fa55c7c73df5a841d7127 --extensions h -- clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h
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<details>
<summary>
View the diff from clang-format here.
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``````````diff
diff --git a/clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h b/clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h
index a24ba86dae..08e6a2e678 100644
--- a/clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h
+++ b/clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h
@@ -248,15 +248,15 @@ public:
                          const CachedFileSystemEntry &Entry) {
     assert(llvm::sys::path::is_absolute_gnu(Filename));
 
-      auto &[CachedEntry, CachedRealPath] = Cache.try_emplace(
-          Filename, &Entry, nullptr).first->getValue();
-    
-      if (!CachedEntry) {
-        assert((!CachedEntry && CachedRealPath) && "entry already present");
-        CachedEntry = &Entry;
-      }
-    
-      return *CachedEntry;
+    auto &[CachedEntry, CachedRealPath] =
+        Cache.try_emplace(Filename, &Entry, nullptr).first->getValue();
+
+    if (!CachedEntry) {
+      assert((!CachedEntry && CachedRealPath) && "entry already present");
+      CachedEntry = &Entry;
+    }
+
+    return *CachedEntry;
   }
 
   /// Returns real path associated with the filename or nullptr if none is
@@ -273,14 +273,14 @@ public:
   insertRealPathForFilename(StringRef Filename,
                             const CachedRealPath &RealPath) {
     assert(llvm::sys::path::is_absolute_gnu(Filename));
-    auto &[CachedEntry, CachedRealPath] = Cache.try_emplace(
-          Filename, nullptr, &RealPath).first->getValue();
-    
+    auto &[CachedEntry, CachedRealPath] =
+        Cache.try_emplace(Filename, nullptr, &RealPath).first->getValue();
+
     if (!CachedRealPath) {
       assert((!CachedRealPath && CachedEntry) && "real path already present");
       CachedRealPath = &RealPath;
     }
-    
+
     return *CachedRealPath;
   }
 };

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https://github.com/llvm/llvm-project/pull/131402