[arcmt] Introduce new '-ccc-arcmt-migrate <path>' ARC migration driver option.

This is a new mode of migration, where we avoid modifying the original files but
we emit temporary files instead.

<path> will be used to keep migration process metadata. Currently the temporary files
that are produced are put in the system's temp directory but we can put them
in the <path> if is necessary.

Also introduce new ARC migration functions in libclang whose only purpose,
currently, is to accept <path> and provide pairs of original file/transformed file
to map from the originals to the files after transformations are applied.

Finally introduce the c-arcmt-test utility that exercises the new libclang functions,
update arcmt-test, and add tests for the whole process.

rdar://9735086.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@134844 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/c-arcmt-test/Makefile b/tools/c-arcmt-test/Makefile
new file mode 100644
index 0000000..6737a53
--- /dev/null
+++ b/tools/c-arcmt-test/Makefile
@@ -0,0 +1,24 @@
+##===- tools/c-arcmt-test/Makefile -------------------------*- Makefile -*-===##
+# 
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+# 
+##===----------------------------------------------------------------------===##
+CLANG_LEVEL := ../..
+
+TOOLNAME = c-arcmt-test
+
+# No plugins, optimize startup time.
+TOOL_NO_EXPORTS = 1
+
+# Don't install this. It is used for tests.
+NO_INSTALL = 1
+
+LINK_COMPONENTS := support mc
+USEDLIBS = clang.a clangIndex.a clangFrontend.a clangDriver.a \
+	   clangSerialization.a clangParse.a clangSema.a \
+	   clangRewrite.a clangAnalysis.a clangAST.a clangLex.a clangBasic.a
+
+include $(CLANG_LEVEL)/Makefile