build_cross_tools_gcc4: Clear "missing" scripts instead of touching files.

This just stops the errors from occuring rather than trying to
rebuild the files at all. This is much cleaner, and solves
a few cases that the other method did not.

build/scripts/build_cross_tools_gcc4

@@ -135,21 +135,12 @@ if [ -z "$gccVersion" ]; then
 	exit 1
 fi
 
-# touch all info files in order to avoid the dependency on makeinfo
-# (which apparently doesn't work reliably on all the different host
-# configurations and changes files which in turn appear as local changes
-# to the VCS).
-find "$binutilsSourceDir" "$gccSourceDir" -name \*.info -print0 | xargs -0 touch
-
-# touch all configure files in order to avoid them being auto-rebuilt,
-# as this often fails because the host system does not have the exact
-# version of autofools that GCC wants
-find "$binutilsSourceDir" "$gccSourceDir" \( -name configure -o -name \*.in \) -print0 | xargs -0 touch
-
-# export some variables to stop the subsequent configure/make from invoking
-# tools which we don't require the user to have installed (or do not require
-# a specific version of, which autofools does.)
-export ACLOCAL=:
+# clear out the "missing" scripts so that they don't cause errors on tools
+# that are not installed, as we will have committed any files generated by
+# them to the buildtools repo already.
+echo "#!/bin/sh" >"$binutilsSourceDir"/missing
+echo "#!/bin/sh" >"$gccSourceDir"/missing
+echo "#!/bin/sh" >"$gccSourceDir"/isl/missing
 
 # create the object and installation directories for the cross compilation tools
 objDir="${installDir}-build"