Move PrependMainExecutablePath next to its only user.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183980 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/bugpoint/ToolRunner.cpp b/tools/bugpoint/ToolRunner.cpp
index 0fea978..a79248d 100644
--- a/tools/bugpoint/ToolRunner.cpp
+++ b/tools/bugpoint/ToolRunner.cpp
@@ -230,6 +230,28 @@
 
 void AbstractInterpreter::anchor() { }
 
+/// Prepend the path to the program being executed
+/// to \p ExeName, given the value of argv[0] and the address of main()
+/// itself. This allows us to find another LLVM tool if it is built in the same
+/// directory. An empty string is returned on error; note that this function
+/// just mainpulates the path and doesn't check for executability.
+/// @brief Find a named executable.
+static sys::Path PrependMainExecutablePath(const std::string &ExeName,
+                                           const char *Argv0, void *MainAddr) {
+  // Check the directory that the calling program is in.  We can do
+  // this if ProgramPath contains at least one / character, indicating that it
+  // is a relative path to the executable itself.
+  sys::Path Result = sys::Path::GetMainExecutable(Argv0, MainAddr);
+  Result.eraseComponent();
+
+  if (!Result.isEmpty()) {
+    Result.appendComponent(ExeName);
+    Result.appendSuffix(sys::Path::GetEXESuffix());
+  }
+
+  return Result;
+}
+
 // LLI create method - Try to find the LLI executable
 AbstractInterpreter *AbstractInterpreter::createLLI(const char *Argv0,
                                                     std::string &Message,