Revert "[clang][Driver] Correct tool search path priority"

Revert 028571d to investigate
MacOS failure.
(also the review link was incorrect, should be
https://reviews.llvm.org/D79842)

clang/lib/Driver/Driver.cpp

@@ -4717,11 +4717,13 @@ void Driver::generatePrefixedToolNames(
 }
 
 static bool ScanDirForExecutable(SmallString<128> &Dir,
-                                 const std::string &Name) {
-  llvm::sys::path::append(Dir, Name);
-  if (llvm::sys::fs::can_execute(Twine(Dir)))
-    return true;
-  llvm::sys::path::remove_filename(Dir);
+                                 ArrayRef<std::string> Names) {
+  for (const auto &Name : Names) {
+    llvm::sys::path::append(Dir, Name);
+    if (llvm::sys::fs::can_execute(Twine(Dir)))
+      return true;
+    llvm::sys::path::remove_filename(Dir);
+  }
   return false;
 }
 
@@ -4734,9 +4736,8 @@ std::string Driver::GetProgramPath(StringRef Name, const ToolChain &TC) const {
   for (const auto &PrefixDir : PrefixDirs) {
     if (llvm::sys::fs::is_directory(PrefixDir)) {
       SmallString<128> P(PrefixDir);
-      for (const auto &TargetSpecificExecutable : TargetSpecificExecutables)
-        if (ScanDirForExecutable(P, TargetSpecificExecutable))
-          return std::string(P.str());
+      if (ScanDirForExecutable(P, TargetSpecificExecutables))
+        return std::string(P.str());
     } else {
       SmallString<128> P((PrefixDir + Name).str());
       if (llvm::sys::fs::can_execute(Twine(P)))
@@ -4745,25 +4746,17 @@ std::string Driver::GetProgramPath(StringRef Name, const ToolChain &TC) const {
   }
 
   const ToolChain::path_list &List = TC.getProgramPaths();
-  for (const auto &TargetSpecificExecutable : TargetSpecificExecutables) {
-    // For each possible name of the tool look for it in
-    // program paths first, then the path.
-    // Higher priority names will be first, meaning that
-    // a higher priority name in the path will be found
-    // instead of a lower priority name in the program path.
-    // E.g. <triple>-gcc on the path will be found instead
-    // of gcc in the program path
-    for (const auto &Path : List) {
-      SmallString<128> P(Path);
-      if (ScanDirForExecutable(P, TargetSpecificExecutable))
-        return std::string(P.str());
-    }
+  for (const auto &Path : List) {
+    SmallString<128> P(Path);
+    if (ScanDirForExecutable(P, TargetSpecificExecutables))
+      return std::string(P.str());
+  }
 
-    // Fall back to the path
+  // If all else failed, search the path.
+  for (const auto &TargetSpecificExecutable : TargetSpecificExecutables)
     if (llvm::ErrorOr<std::string> P =
             llvm::sys::findProgramByName(TargetSpecificExecutable))
       return *P;
-  }
 
   return std::string(Name);
 }

clang/test/lit.cfg.py

@@ -46,8 +46,6 @@
 config.substitutions.append(
     ('%src_include_dir', config.clang_src_dir + '/include'))
 
-config.substitutions.append(
-    ('%target_triple', config.target_triple))
 
 # Propagate path to symbolizer for ASan/MSan.
 llvm_config.with_system_environment(