let make checkout of llvm/clang preserve the original directory hierarchy

[Vladimir Kirillov <proger%wilab.org.ua@localhost>]

Hi!

Since NetBSD tree has it's own set of makefiles to build
llvm/clang libraries piece-by-piece, there was no need to preserve
original directory hierarchy of two trees.

However in order to most of makefiles inside that tree
rely on clang's srcdir be inside llvm/tools
(for example, to build clang api documentation).

Would anyone object?

Index: Makefile.inc
===================================================================
RCS file: /cvsroot/src/external/bsd/llvm/Makefile.inc,v
retrieving revision 1.5
diff -u -p -r1.5 Makefile.inc
--- Makefile.inc        21 Mar 2011 16:50:12 -0000      1.5
+++ Makefile.inc        19 Apr 2011 06:10:51 -0000
@@ -9,7 +9,7 @@ LLVM_REVISION=  127996
 CLANG_REVISION=        127996
 
 LLVM_SRCDIR:=  ${.PARSEDIR}/dist/llvm
-CLANG_SRCDIR:= ${.PARSEDIR}/dist/clang
+CLANG_SRCDIR:= ${LLVM_SRCDIR}/tools/clang
 LLVM_TOPLEVEL:=        ${.PARSEDIR}
 
 CPPFLAGS+=     -I. -I${LLVM_SRCDIR}/include -I${CLANG_SRCDIR}/include \