graphics/opencv: fix build with LLVM 13 on powerpc64le

/wrkdirs/usr/ports/graphics/opencv/work/opencv-4.5.5/modules/core/include/opencv2/core/vsx_utils.hpp:352:12: warning: 'vec_permi' macro redefined [-Wmacro-redefined]
           ^
/usr/lib/clang/13.0.0/include/altivec.h:13077:9: note: previous definition is here
        ^
/wrkdirs/usr/ports/graphics/opencv/work/opencv-4.5.5/modules/core/include/opencv2/core/vsx_utils.hpp:370:25: error: redefinition of 'vec_promote'
VSX_FINLINE(vec_dword2) vec_promote(long long a, int b)
                        ^
/usr/lib/clang/13.0.0/include/altivec.h:14604:1: note: previous definition is here
vec_promote(signed long long __a, int __b) {
^
/wrkdirs/usr/ports/graphics/opencv/work/opencv-4.5.5/modules/core/include/opencv2/core/vsx_utils.hpp:377:26: error: redefinition of 'vec_promote'
VSX_FINLINE(vec_udword2) vec_promote(unsigned long long a, int b)
                         ^
/usr/lib/clang/13.0.0/include/altivec.h:14611:1: note: previous definition is here
vec_promote(unsigned long long __a, int __b) {
^
/wrkdirs/usr/ports/graphics/opencv/work/opencv-4.5.5/modules/core/include/opencv2/core/hal/intrin_vsx.hpp:1045:22: error: call to 'vec_rsqrt' is ambiguous
{ return v_float32x4(vec_rsqrt(x.val)); }
                     ^~~~~~~~~
/usr/lib/clang/13.0.0/include/altivec.h:8472:34: note: candidate function
static vector float __ATTRS_o_ai vec_rsqrt(vector float __a) {
                                 ^
/wrkdirs/usr/ports/graphics/opencv/work/opencv-4.5.5/modules/core/include/opencv2/core/vsx_utils.hpp:362:29: note: candidate function
    VSX_FINLINE(vec_float4) vec_rsqrt(const vec_float4& a)
                            ^
/wrkdirs/usr/ports/graphics/opencv/work/opencv-4.5.5/modules/core/include/opencv2/core/hal/intrin_vsx.hpp:1047:22: error: call to 'vec_rsqrt' is ambiguous
{ return v_float64x2(vec_rsqrt(x.val)); }
                     ^~~~~~~~~
/usr/lib/clang/13.0.0/include/altivec.h:8477:35: note: candidate function
static vector double __ATTRS_o_ai vec_rsqrt(vector double __a) {
                                  ^
/wrkdirs/usr/ports/graphics/opencv/work/opencv-4.5.5/modules/core/include/opencv2/core/vsx_utils.hpp:365:30: note: candidate function
    VSX_FINLINE(vec_double2) vec_rsqrt(const vec_double2& a)
                             ^
1 warning and 4 errors generated.

1 files changed, 33 insertions, 0 deletions

diff --git a/graphics/opencv/files/patch-modules_core_include_opencv2_core_vsx__utils.hpp b/graphics/opencv/files/patch-modules_core_include_opencv2_core_vsx__utils.hpp
new file mode 100644
index 000000000000..4802cdfb7ec5
--- /dev/null
+++ b/graphics/opencv/files/patch-modules_core_include_opencv2_core_vsx__utils.hpp
@@ -0,0 +1,33 @@
+--- modules/core/include/opencv2/core/vsx_utils.hpp.orig	2022-03-21 01:40:15 UTC
++++ modules/core/include/opencv2/core/vsx_utils.hpp
+@@ -324,6 +324,7 @@ VSX_IMPL_1RG(vec_udword2, vec_float4,  xvcvspuxds, vec
+ #define VSX_IMPL_CONVERT(rt, rg, fnm) \
+ VSX_FINLINE(rt) fnm(const rg& a) { return __builtin_convertvector(a, rt); }
+ 
++#ifndef vec_permi
+ #if __clang_major__ < 5
+ // implement vec_permi in a dirty way
+ #   define VSX_IMPL_CLANG_4_PERMI(Tvec)                                                 \
+@@ -351,12 +352,14 @@ VSX_FINLINE(rt) fnm(const rg& a) { return __builtin_co
+ // vec_xxpermdi is missing little-endian supports in clang 4 just like gcc4
+ #   define vec_permi(a, b, c) vec_xxpermdi(b, a, (3 ^ (((c) & 1) << 1 | (c) >> 1)))
+ #endif // __clang_major__ < 5
++#endif // vec_permi
+ 
+ // shift left double by word immediate
+ #ifndef vec_sldw
+ #   define vec_sldw vec_xxsldwi
+ #endif
+ 
++#if __clang_major__ < 13
+ // Implement vec_rsqrt since clang only supports vec_rsqrte
+ #ifndef vec_rsqrt
+     VSX_FINLINE(vec_float4) vec_rsqrt(const vec_float4& a)
+@@ -380,6 +383,7 @@ VSX_FINLINE(vec_udword2) vec_promote(unsigned long lon
+     ret[b & 1] = a;
+     return ret;
+ }
++#endif
+ 
+ // vec_popcnt should return unsigned but clang has different thought just like gcc in vec_vpopcnt
+ #define VSX_IMPL_POPCNTU(Tvec, Tvec2, ucast)   \