Add a dummy file in each subdirectory in test/Driver/Inputs/hexagon_tree

Git does not store empty subdirectories (while SVN does). Git clone of
the clang repository did not create the fake Hexagon installation tree
used for testing the driver. This only became evident after a change
in the Hexagon toolchain that started checking for existence of certain
directories.

llvm-svn: 284402

clang/test/Driver/Inputs/hexagon_tree/Tools/bin/readme

@@ -0,0 +1,4 @@
+Git does not record empty directories. Create a dummy file in each directory
+here. Strictly speaking, putting dummy files in leaf directories should be
+sufficient, but adding them everywhere reduces the risk of repeating the same
+problem in case new directories are added.

clang/test/Driver/Inputs/hexagon_tree/Tools/readme

@@ -0,0 +1,4 @@
+Git does not record empty directories. Create a dummy file in each directory
+here. Strictly speaking, putting dummy files in leaf directories should be
+sufficient, but adding them everywhere reduces the risk of repeating the same
+problem in case new directories are added.

clang/test/Driver/Inputs/hexagon_tree/Tools/target/hexagon/include/c++/readme

@@ -0,0 +1,4 @@
+Git does not record empty directories. Create a dummy file in each directory
+here. Strictly speaking, putting dummy files in leaf directories should be
+sufficient, but adding them everywhere reduces the risk of repeating the same
+problem in case new directories are added.

clang/test/Driver/Inputs/hexagon_tree/Tools/target/hexagon/include/readme

@@ -0,0 +1,4 @@
+Git does not record empty directories. Create a dummy file in each directory
+here. Strictly speaking, putting dummy files in leaf directories should be
+sufficient, but adding them everywhere reduces the risk of repeating the same
+problem in case new directories are added.

clang/test/Driver/Inputs/hexagon_tree/Tools/target/hexagon/readme

@@ -0,0 +1,4 @@
+Git does not record empty directories. Create a dummy file in each directory
+here. Strictly speaking, putting dummy files in leaf directories should be
+sufficient, but adding them everywhere reduces the risk of repeating the same
+problem in case new directories are added.

clang/test/Driver/Inputs/hexagon_tree/Tools/target/readme

@@ -0,0 +1,4 @@
+Git does not record empty directories. Create a dummy file in each directory
+here. Strictly speaking, putting dummy files in leaf directories should be
+sufficient, but adding them everywhere reduces the risk of repeating the same
+problem in case new directories are added.