mingw-w64: install gl *.pc files here instead of mxe-conf

src/mingw-w64.mk

@@ -9,7 +9,7 @@ $(PKG)_CHECKSUM := 2a601db99ef579b9be69c775218ad956a24a09d7dabc9ff6c5bd60da9ccc9
 $(PKG)_SUBDIR   := $(PKG)-v$($(PKG)_VERSION)
 $(PKG)_FILE     := $(PKG)-v$($(PKG)_VERSION).tar.bz2
 $(PKG)_URL      := https://$(SOURCEFORGE_MIRROR)/project/$(PKG)/$(PKG)/$(PKG)-release/$($(PKG)_FILE)
-$(PKG)_TYPE     := archive
+$(PKG)_TYPE     := script
 $(PKG)_DEPS     :=
 
 define $(PKG)_UPDATE
@@ -18,3 +18,22 @@ define $(PKG)_UPDATE
     $(SORT) -V | \
     tail -1
 endef
+
+# can't install headers here since dummy pthreads headers are installed
+# and then clobbered by inline winpthreads build in gcc (see #958)
+
+define $(PKG)_BUILD
+    # create pkg-config files for OpenGL/GLU
+    mkdir -p '$(PREFIX)/$(TARGET)/lib/pkgconfig'
+    (echo 'Name: gl'; \
+     echo 'Version: 0'; \
+     echo 'Description: OpenGL'; \
+     echo 'Libs: -lopengl32';) \
+     > '$(PREFIX)/$(TARGET)/lib/pkgconfig/gl.pc'
+
+    (echo 'Name: glu'; \
+     echo 'Version: 0'; \
+     echo 'Description: OpenGL'; \
+     echo 'Libs: -lglu32';) \
+     > '$(PREFIX)/$(TARGET)/lib/pkgconfig/glu.pc'
+endef

src/mxe-conf.mk

@@ -15,20 +15,6 @@ define $(PKG)_BUILD
     # install target-specific autotools config file
     # setting ac_cv_build bypasses the config.guess check in every package
     echo "ac_cv_build=$(BUILD)" > '$(PREFIX)/$(TARGET)/share/config.site'
-
-    # create pkg-config files for OpenGL/GLU
-    mkdir -p '$(PREFIX)/$(TARGET)/lib/pkgconfig'
-    (echo 'Name: gl'; \
-     echo 'Version: 0'; \
-     echo 'Description: OpenGL'; \
-     echo 'Libs: -lopengl32';) \
-     > '$(PREFIX)/$(TARGET)/lib/pkgconfig/gl.pc'
-    (echo 'Name: glu'; \
-     echo 'Version: 0'; \
-     echo 'Description: OpenGL'; \
-     echo 'Libs: -lglu32';) \
-     > '$(PREFIX)/$(TARGET)/lib/pkgconfig/glu.pc'
-
 endef
 
 define $(PKG)_BUILD_$(BUILD)