[m-rev.] trivial diff: fix stage 2 boehm_gc with MSVC

[Julien Fischer]

Fix compilation of the stage 2 Boehm GC with MSVC.

tools/bootcheck:
	Copy a file required by MSVC into the stage 2 boehm_gc
	directory.

Julien.

diff --git a/tools/bootcheck b/tools/bootcheck
index ca74495..a3197b3 100755
--- a/tools/bootcheck
+++ b/tools/bootcheck
@@ -769,6 +769,7 @@ then
             cp $root/boehm_gc/Makefile.direct .
             cp $root/boehm_gc/NT_MAKEFILE .
             cp $root/boehm_gc/gc_cpp.cc .
+            cp $root/boehm_gc/gc_cpp.cpp .
             cp $root/boehm_gc/build_atomic_ops.sh* .
             cp -r $root/boehm_gc/libatomic_ops-*[0-9] .
             cp -r $root/boehm_gc/libatomic_ops .