Upgrade GCC to 5.2.0 for Windows x86 and x86_64

This patch does a few things

- Moved GHC x86 to MinGW-w64 (Using Awson's patch)
- Moves Both GHCs to MSYS2 toolchains
- Completely removes the dependencies on the git tarball repo
  - Downloads only the required tarball for the architecture for
    which we are building
  - Downloads the perl tarball is missing as well
  - Fixed a few bugs in the linker to fix tests on Windows

The links currently point to repo.msys2.org and GitHub, it might be
more desirable to mirror them on
http://downloads.haskell.org/~ghc/mingw/ as with the previous patch
attempt.

For more details on what the MSYS2 packages I include see #10726
(Awson's comment). but it should contain all we need
and no python or fortran, which makes the uncompressed tar a 1-2
hundreds mb smaller.

The `GCC 5.2.0` in the package supports `libgcc` as a shared library,
this is a problem since
when compiling with -shared the produced dll now has a dependency on
`libgcc_s_sjlj-1.dll`.
To solve this the flag `-static-libgcc` is now being used for all GCC
calls on windows.

Test Plan:
./validate was ran both on x86 and x86_64 windows and compared against
the baseline.

A few test were failing due to Ld no longer being noisy. These were
updated.

The changes to the configure script *should* be validated by the build
bots for the other platforms before landing

Reviewers: simonmar, awson, bgamari, austin, thomie

Reviewed By: thomie

Subscribers: #ghc_windows_task_force, thomie, awson

Differential Revision: https://phabricator.haskell.org/D1123

GHC Trac Issues: #10726, #9014, #9218, #10435

1 files changed, 7 insertions, 3 deletions

diff --git a/driver/gcc/gcc.c b/driver/gcc/gcc.c
index ea1f480b4d..517b008a12 100644
--- a/driver/gcc/gcc.c
+++ b/driver/gcc/gcc.c
@@ -47,9 +47,13 @@ int main(int argc, char** argv) {
        from that in preference to the in-tree files. */
     preArgv[0] = mkString("-B%s", binDir);
     preArgv[1] = mkString("-B%s/../lib", binDir);
-    preArgv[2] = mkString("-B%s/../lib/gcc/mingw32/4.5.2", binDir);
-    preArgv[3] = mkString("-B%s/../libexec/gcc/mingw32/4.5.2", binDir);
-
+#ifdef __MINGW64__
+    preArgv[2] = mkString("-B%s/../lib/gcc/x86_64-w64-mingw32/5.2.0", binDir);
+    preArgv[3] = mkString("-B%s/../libexec/gcc/x86_64-w64-mingw32/5.2.0", binDir);
+#else
+    preArgv[2] = mkString("-B%s/../lib/gcc/i686-w64-mingw32/5.2.0", binDir);
+    preArgv[3] = mkString("-B%s/../libexec/gcc/i686-w64-mingw32/5.2.0", binDir);
+#endif
     run(exePath, 4, preArgv, argc - 1, argv + 1);
 }