opencv: Fix build with clang

Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-oe/recipes-support/opencv/opencv/0001-Check-for-clang-before-using-isystem.patch

@@ -0,0 +1,32 @@
+From fa76d8646bb2b9b514728eeef41afed7c43a36f2 Mon Sep 17 00:00:00 2001
+From: Khem Raj <raj.khem@gmail.com>
+Date: Tue, 11 Sep 2018 18:18:33 -0700
+Subject: [PATCH] Check for clang before using -isystem
+
+When cross compiling with clang, the internal C++ headers are not found
+when adding sysroot to -isystem, that is redundant anyway because it
+will look for headers insider --sysroot path with same quality as it
+would do with -isystem otherwise
+
+Upstream-Status: Submitted [https://github.com/opencv/opencv/pull/12504]
+Signed-off-by: Khem Raj <raj.khem@gmail.com>
+---
+ cmake/OpenCVUtils.cmake | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/cmake/OpenCVUtils.cmake b/cmake/OpenCVUtils.cmake
+index fae91c165f..60c20192dc 100644
+--- a/cmake/OpenCVUtils.cmake
++++ b/cmake/OpenCVUtils.cmake
+@@ -259,7 +259,7 @@ function(ocv_include_directories)
+     ocv_is_opencv_directory(__is_opencv_dir "${dir}")
+     if(__is_opencv_dir)
+       list(APPEND __add_before "${dir}")
+-    elseif(CV_GCC AND NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS "6.0" AND
++    elseif(((CV_GCC AND NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS "6.0") OR CV_CLANG) AND
+            dir MATCHES "/usr/include$")
+       # workaround for GCC 6.x bug
+     else()
+-- 
+2.18.0
+

meta-oe/recipes-support/opencv/opencv/0001-Dont-use-isystem.patch

@@ -0,0 +1,30 @@
+From 7144c44ec70dee73a628463b99ffeed74b1a8ef6 Mon Sep 17 00:00:00 2001
+From: Khem Raj <raj.khem@gmail.com>
+Date: Tue, 11 Sep 2018 00:21:18 -0700
+Subject: [PATCH] Dont use isystem
+
+clang really does not like it
+
+Upstream-Status: Pending
+
+Signed-off-by: Khem Raj <raj.khem@gmail.com>
+---
+ cmake/OpenCVPCHSupport.cmake | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/cmake/OpenCVPCHSupport.cmake b/cmake/OpenCVPCHSupport.cmake
+index f9b1b48b65..fe27a136f5 100644
+--- a/cmake/OpenCVPCHSupport.cmake
++++ b/cmake/OpenCVPCHSupport.cmake
+@@ -18,6 +18,8 @@ IF(CV_GCC)
+         SET(PCHSupport_FOUND TRUE)
+     ENDIF()
+ 
++    SET(CMAKE_INCLUDE_SYSTEM_FLAG_C "-I")
++    SET(CMAKE_INCLUDE_SYSTEM_FLAG_CXX "-I")
+     SET(_PCH_include_prefix "-I")
+     SET(_PCH_isystem_prefix "-isystem")
+     SET(_PCH_define_prefix "-D")
+-- 
+2.18.0
+

meta-oe/recipes-support/opencv/opencv_3.4.3.bb

@@ -51,6 +51,8 @@ SRC_URI = "git://github.com/opencv/opencv.git;name=opencv \
     file://0003-To-fix-errors-as-following.patch \
     file://fixpkgconfig.patch \
     file://0001-Temporarliy-work-around-deprecated-ffmpeg-RAW-functi.patch \
+    file://0001-Dont-use-isystem.patch \
+    file://0001-Check-for-clang-before-using-isystem.patch \
 "
 PV = "3.4.3+git${SRCPV}"