Reinstate downloading old versions of winrpm gcc dll's (#18059)

This mostly reverts #17906 and puts #15521 back in place,
but from a slightly more permanent download location now.

Unfortunately using the latest opensuse copy of the gcc dll's
is causing issues when a cygwin-built Julia tries to load an
opensuse-built libzmq.dll. Using these slightly old gcc 5 versions
seems to fix it. I suspect the difference is which libstdc++ ABI
is being used. GCC 5 has both old and new available, but many distros
had it using the old ABI by default for compatibility. GCC 6 (which
opensuse is using now) is more likely to be using the new ABI by
default.
(cherry picked from commit 7b4077f)

Makefile

@@ -438,7 +438,7 @@ endif
 
 ifeq ($(OS), WINNT)
  [ ! -d dist-extras ] || ( cd dist-extras && \
- cp 7z.exe 7z.dll libexpat-1.dll zlib1.dll $(bindir) && \
+ cp 7z.exe 7z.dll libexpat-1.dll zlib1.dll libgfortran-3.dll libquadmath-0.dll libstdc++-6.dll libgcc_s_s*-1.dll libssp-0.dll $(bindir) && \
  mkdir $(DESTDIR)$(prefix)/Git && \
  7z x PortableGit.7z -o"$(DESTDIR)$(prefix)/Git" && \
  echo "[core] eol = lf" >> "$(GITCONFIG)" && \
@@ -562,7 +562,14 @@ ifneq (,$(filter $(ARCH), i386 i486 i586 i686))
  $(JLDOWNLOAD) http://downloads.sourceforge.net/sevenzip/7z920.exe && \
  7z x -y 7z920.exe 7z.exe 7z.dll && \
  ../contrib/windows/winrpm.sh http://download.opensuse.org/repositories/windows:/mingw:/win32/openSUSE_13.2 \
- "mingw32-libgfortran3 mingw32-libquadmath0 mingw32-libstdc++6 mingw32-libgcc_s_sjlj1 mingw32-libssp0 mingw32-libexpat1 mingw32-zlib1" && \
+ "mingw32-libexpat1 mingw32-zlib1" && \
+ $(JLDOWNLOAD) https://julialang.s3.amazonaws.com/bin/winnt/extras/mingw32-libgfortran3-5.3.0-1.1.noarch.rpm && \
+ $(JLDOWNLOAD) https://julialang.s3.amazonaws.com/bin/winnt/extras/mingw32-libquadmath0-5.3.0-1.1.noarch.rpm && \
+ $(JLDOWNLOAD) https://julialang.s3.amazonaws.com/bin/winnt/extras/mingw32-libstdc++6-5.3.0-1.1.noarch.rpm && \
+ $(JLDOWNLOAD) https://julialang.s3.amazonaws.com/bin/winnt/extras/mingw32-libgcc_s_sjlj1-5.3.0-1.1.noarch.rpm && \
+ $(JLDOWNLOAD) https://julialang.s3.amazonaws.com/bin/winnt/extras/mingw32-libssp0-5.3.0-1.1.noarch.rpm && \
+ for i in *.rpm; do 7z x -y $$i; done && \
+ for i in *.cpio; do 7z x -y $$i; done && \
  cp usr/i686-w64-mingw32/sys-root/mingw/bin/*.dll . && \
  $(JLDOWNLOAD) PortableGit.7z https://github.com/git-for-windows/git/releases/download/v2.6.1.windows.1/PortableGit-2.6.1-32-bit.7z.exe
 else ifeq ($(ARCH),x86_64)
@@ -572,7 +579,14 @@ else ifeq ($(ARCH),x86_64)
  mv _7z.dll 7z.dll && \
  mv _7z.exe 7z.exe && \
  ../contrib/windows/winrpm.sh http://download.opensuse.org/repositories/windows:/mingw:/win64/openSUSE_13.2 \
- "mingw64-libgfortran3 mingw64-libquadmath0 mingw64-libstdc++6 mingw64-libgcc_s_seh1 mingw64-libssp0 mingw64-libexpat1 mingw64-zlib1" && \
+ "mingw64-libexpat1 mingw64-zlib1" && \
+ $(JLDOWNLOAD) https://julialang.s3.amazonaws.com/bin/winnt/extras/mingw64-libgfortran3-5.3.0-1.1.noarch.rpm && \
+ $(JLDOWNLOAD) https://julialang.s3.amazonaws.com/bin/winnt/extras/mingw64-libquadmath0-5.3.0-1.1.noarch.rpm && \
+ $(JLDOWNLOAD) https://julialang.s3.amazonaws.com/bin/winnt/extras/mingw64-libstdc++6-5.3.0-1.1.noarch.rpm && \
+ $(JLDOWNLOAD) https://julialang.s3.amazonaws.com/bin/winnt/extras/mingw64-libgcc_s_seh1-5.3.0-1.1.noarch.rpm && \
+ $(JLDOWNLOAD) https://julialang.s3.amazonaws.com/bin/winnt/extras/mingw64-libssp0-5.3.0-1.1.noarch.rpm && \
+ for i in *.rpm; do 7z x -y $$i; done && \
+ for i in *.cpio; do 7z x -y $$i; done && \
  cp usr/x86_64-w64-mingw32/sys-root/mingw/bin/*.dll . && \
  $(JLDOWNLOAD) PortableGit.7z https://github.com/git-for-windows/git/releases/download/v2.6.1.windows.1/PortableGit-2.6.1-64-bit.7z.exe
 else