Move ExecuteCompilerInvocation to a new library FrontendTool

r110903 introduced a dependency from Frontend to every library that
declared an Action by introducing Action references that previously
resided in the driver in the file ExecuteCompilerInvocation.cpp.
This patch moves ExecuteCompilerInvocation to a new library named
FrontendTool which is intended to bear these dependencies.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@111873 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/FrontendTool/Makefile b/lib/FrontendTool/Makefile
new file mode 100644
index 0000000..c43213f
--- /dev/null
+++ b/lib/FrontendTool/Makefile
@@ -0,0 +1,13 @@
+##===- clang/lib/FrontendTool/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 := ../..
+LIBRARYNAME := clangFrontendTool
+
+include $(CLANG_LEVEL)/Makefile