[OpenBLAS] Add hang-on-exit patch (#353)

This is the patch from JuliaLang/julia#34225, but
against 0.3.7 not 0.3.5.

O/OpenBLAS/build_tarballs.jl

@@ -71,7 +71,9 @@ fi
 
 
 # Enter the fun zone
-cd ${WORKSPACE}/srcdir/OpenBLAS-*/
+cd ${WORKSPACE}/srcdir/OpenBLAS*/
+
+atomic_patch -p1 ${WORKSPACE}/srcdir/patches/openblas-winexit.patch
 
 # Build the actual library
 make "${flags[@]}"

O/OpenBLAS/bundled/patches/openblas-winexit.patch

@@ -0,0 +1,27 @@
+commit b16fa2e7111dc4dc1d9d987bd5dcbf89c82b9ee8
+Author: Keno Fischer <[email protected]>
+Date:   Sun Dec 29 15:08:13 2019 -0500
+
+    win32: Don't run cleanup if we're about to exit anyway
+
+    If the process is about to exit, there's no point trying to do
+    a bunch of work to clean up resources. The kernel will release
+    them much more efficiently when the process exits at the end
+    of this function.
+
+diff --git a/exports/dllinit.c b/exports/dllinit.c
+index 4a05c0e1..88f9af65 100644
+--- a/exports/dllinit.c
++++ b/exports/dllinit.c
+@@ -50,7 +50,10 @@ BOOL APIENTRY DllMain(HINSTANCE hInst, DWORD reason, LPVOID reserved) {
+         gotoblas_init();
+         break;
+       case DLL_PROCESS_DETACH:
+-        gotoblas_quit();
++        // If the process is about to exit, don't bother releasing any resources
++        // The kernel is much better at bulk releasing then.
++        if (!reserved)
++          gotoblas_quit();
+         break;
+       case DLL_THREAD_ATTACH:
+         break;