[RC1] Building clang/llvm on Cygwin-1.7

Hello guys,

On cygwin-1.7, I can build and test clang successfully by 3-stage.

Known issues:

  - binaries among stage2 and stage3 do not match. (other than
timestamp and checksum)
    investigating.
  - I met some warnings. I have fixes for them.
    - [llvm] r127241
    - [llvm] http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20110307/117725.html
    - [clang] r127283
    - [clang] r127308
  - It seems generated binaries are too slow to start up. I guess
regardless of "rebasing issue".

ps. I will abandon cygwin-1.5 any more.

...Takumi

CYGWIN_NT-6.1-WOW64 HEAVEN64 1.7.7(0.230/5/3) 2010-08-31 09:58 i686 Cygwin

****stage1

g++ (GCC) 4.3.4 20090804 (release) 1
Copyright (C) 2008 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

llvm config.status 2.9svn
configured by ../../llvm/configure, generated by GNU Autoconf 2.60,
  with options "'-C' '--enable-targets=all' '--enable-optimized'
'--prefix=/cygdrive/e/llvm/build/cygwin-static/install/stage1'
'--with-optimize-option=-O3 -Werror'"

-- Testing: 8767 tests, 1 threads --

Testing Time: 6746.50s
  Expected Passes : 8149
  Expected Failures : 71
  Unsupported Tests : 547

****stage2
llvm config.status 2.9svn
configured by ../../../llvm/configure, generated by GNU Autoconf 2.60,
  with options "'-C' '--enable-targets=all' '--enable-optimized'
'--disable-assertions'
'--prefix=/cygdrive/e/llvm/build/cygwin-static/stage2/../install/stage2'
'--with-optimize-option=-O3 -Werror'
'CC=/cygdrive/e/llvm/build/cygwin-static/stage2/../Release+Asserts/bin/clang.exe'
'CXX=/cygdrive/e/llvm/build/cygwin-static/stage2/../Release+Asserts/bin/clang++.exe'"

-- Testing: 8758 tests, 1 threads --

Testing Time: 6047.76s
  Expected Passes : 8140
  Expected Failures : 71
  Unsupported Tests : 547

****stage3

llvm config.status 2.9svn
configured by ../../../llvm/configure, generated by GNU Autoconf 2.60,
  with options "'-C' '--enable-targets=all' '--enable-optimized'
'--disable-assertions'
'--prefix=/cygdrive/e/llvm/build/cygwin-static/install/stage3'
'--with-optimize-option=-O3 -Werror'
'CC=/cygdrive/e/llvm/build/cygwin-static/stage2/Release/bin/clang.exe'
'CXX=/cygdrive/e/llvm/build/cygwin-static/stage2/Release/bin/clang++.exe'"

-- Testing: 8758 tests, 1 threads --

Testing Time: 7687.44s
  Expected Passes : 8140
  Expected Failures : 71
  Unsupported Tests : 547