Fix CI hangs on win32

deps/blas.mk

@@ -99,7 +99,12 @@ $(BUILDDIR)/$(OPENBLAS_SRC_DIR)/openblas-skylakexdgemm.patch-applied: $(BUILDDIR
 		patch -p1 -f < $(SRCDIR)/patches/openblas-skylakexdgemm.patch
 	echo 1 > $@
 
-$(BUILDDIR)/$(OPENBLAS_SRC_DIR)/build-configured: $(BUILDDIR)/$(OPENBLAS_SRC_DIR)/openblas-skylakexdgemm.patch-applied
+$(BUILDDIR)/$(OPENBLAS_SRC_DIR)/openblas-winexit.patch-applied: $(BUILDDIR)/$(OPENBLAS_SRC_DIR)/source-extracted
+	cd $(BUILDDIR)/$(OPENBLAS_SRC_DIR) && \
+		patch -p1 -f < $(SRCDIR)/patches/openblas-winexit.patch
+	echo 1 > $@
+
+$(BUILDDIR)/$(OPENBLAS_SRC_DIR)/build-configured: $(BUILDDIR)/$(OPENBLAS_SRC_DIR)/openblas-skylakexdgemm.patch-applied $(BUILDDIR)/$(OPENBLAS_SRC_DIR)/openblas-winexit.patch-applied
 	echo 1 > $@
 
 $(BUILDDIR)/$(OPENBLAS_SRC_DIR)/build-compiled: $(BUILDDIR)/$(OPENBLAS_SRC_DIR)/build-configured

deps/patches/openblas-winexit.patch

@@ -0,0 +1,27 @@
+commit 7f4a96a353c06c2fdecb0b2464800bcf8fab6fd7
+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 02ff092e..56aafa95 100644
+--- a/exports/dllinit.c
++++ b/exports/dllinit.c
+@@ -48,7 +48,10 @@ BOOL APIENTRY DllMain(HINSTANCE hInst, DWORD reason, LPVOID reserved) {
+   }
+
+   if (reason == 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();
+   }
+
+   return TRUE;