Build libcxx and libcxxabi statically for armv7 and test building a C++ hello world

patches/mingw-0001.patch

@@ -0,0 +1,42 @@
+From 8dedb3528699061cab1fde4c80847ee492226d42 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Martin=20Storsj=C3=B6?= <martin@martin.st>
+Date: Fri, 25 Aug 2017 10:55:45 +0300
+Subject: [PATCH 1/2] headers: Add casts in ua_wcs*chr in stralign.h
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+When building libcxx, a version of wcschr that returns const
+is provided, breaking compilation here since the return from
+wcschr is returned directly as if it were a const pointer.
+By adding these casts, compilation succeeds.
+
+This matches the calls to uaw_wcschr and uaw_wcsrchr directly
+below, having similar casts.
+
+Signed-off-by: Martin Storsjö <martin@martin.st>
+---
+ mingw-w64-headers/include/stralign.h | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/mingw-w64-headers/include/stralign.h b/mingw-w64-headers/include/stralign.h
+index 9b5637d..f4d9d6d 100644
+--- a/mingw-w64-headers/include/stralign.h
++++ b/mingw-w64-headers/include/stralign.h
+@@ -118,11 +118,11 @@ extern "C" {
+ 
+ #ifndef __CRT__NO_INLINE
+   __CRT_INLINE PUWSTR_C ua_wcschr(PCUWSTR String,WCHAR Character) {
+-    if(WSTR_ALIGNED(String)) return wcschr((PCWSTR)String,Character);
++    if(WSTR_ALIGNED(String)) return (PUWSTR_C)wcschr((PCWSTR)String,Character);
+     return (PUWSTR_C)uaw_wcschr(String,Character);
+   }
+   __CRT_INLINE PUWSTR_C ua_wcsrchr(PCUWSTR String,WCHAR Character) {
+-    if(WSTR_ALIGNED(String)) return wcsrchr((PCWSTR)String,Character);
++    if(WSTR_ALIGNED(String)) return (PUWSTR_C)wcsrchr((PCWSTR)String,Character);
+     return (PUWSTR_C)uaw_wcsrchr(String,Character);
+   }
+ #if defined(__cplusplus) && defined(_WConst_Return)
+-- 
+2.7.4
+