Use new utility function to clean leading junk from pathnames. NFC

llvm-svn: 246714
diff --git a/clang/lib/Frontend/DependencyFile.cpp b/clang/lib/Frontend/DependencyFile.cpp
index c5c3449..93d4a80 100644
--- a/clang/lib/Frontend/DependencyFile.cpp
+++ b/clang/lib/Frontend/DependencyFile.cpp
@@ -51,15 +51,8 @@
     if (!FE)
       return;
 
-    StringRef Filename = FE->getName();
-
-    // Remove leading "./" (or ".//" or "././" etc.)
-    while (Filename.size() > 2 && Filename[0] == '.' &&
-           llvm::sys::path::is_separator(Filename[1])) {
-      Filename = Filename.substr(1);
-      while (llvm::sys::path::is_separator(Filename[0]))
-        Filename = Filename.substr(1);
-    }
+    StringRef Filename =
+        llvm::sys::path::remove_leading_dotslash(FE->getName());
 
     DepCollector.maybeAddDependency(Filename, /*FromModule*/false,
                                    FileType != SrcMgr::C_User,
@@ -295,15 +288,7 @@
   if (!FileMatchesDepCriteria(Filename.data(), FileType))
     return;
 
-  // Remove leading "./" (or ".//" or "././" etc.)
-  while (Filename.size() > 2 && Filename[0] == '.' &&
-         llvm::sys::path::is_separator(Filename[1])) {
-    Filename = Filename.substr(1);
-    while (llvm::sys::path::is_separator(Filename[0]))
-      Filename = Filename.substr(1);
-  }
-    
-  AddFilename(Filename);
+  AddFilename(llvm::sys::path::remove_leading_dotslash(Filename));
 }
 
 void DFGImpl::InclusionDirective(SourceLocation HashLoc,