Revert "Add --program-prefix support to build"

The Apple buildbots are set up to pass --target to configure for both
cross- and non-cross-compile builds, and the standard autoconf response
to this is to set the program prefix to '<target>-'. Until we can figure
out the proper way to handle this (don't pass --target? pass an explicit
--program-prefix=""? don't auto-populate program_prefix with target_alias?)
it's more important to keep the buildbots running.

This reverts r164633 / ba48ceb1a3802e20e781ef04ea2573ffae2ac414.

llvm-svn: 164651
diff --git a/llvm/projects/sample/Makefile.llvm.rules b/llvm/projects/sample/Makefile.llvm.rules
index 7ed1c1b..a655302 100644
--- a/llvm/projects/sample/Makefile.llvm.rules
+++ b/llvm/projects/sample/Makefile.llvm.rules
@@ -1437,7 +1437,7 @@
 uninstall-local::
 	$(Echo) Uninstall circumvented with NO_INSTALL
 else
-DestTool = $(DESTDIR)$(PROJ_bindir)/$(program_prefix)$(TOOLEXENAME)
+DestTool = $(DESTDIR)$(PROJ_bindir)/$(TOOLEXENAME)
 
 install-local:: $(DestTool)
 
@@ -1451,7 +1451,7 @@
 
 # TOOLALIAS install.
 ifdef TOOLALIAS
-DestToolAlias = $(DESTDIR)$(PROJ_bindir)/$(program_prefix)$(TOOLALIAS)$(EXEEXT)
+DestToolAlias = $(DESTDIR)$(PROJ_bindir)/$(TOOLALIAS)$(EXEEXT)
 
 install-local:: $(DestToolAlias)