add Debian patch to fix build

0003-detect512-is-needed-on-all-architectures.patch

@@ -0,0 +1,35 @@
+From: Adam Sampson <unknown@bitbucket>
+Date: Sun, 14 Oct 2018 14:04:18 +0200
+Subject: detect512 is needed on all architectures
+
+---
+ source/common/cpu.cpp | 9 +++++----
+ 1 file changed, 5 insertions(+), 4 deletions(-)
+
+diff --git a/source/common/cpu.cpp b/source/common/cpu.cpp
+index 0681ff5..fa687da 100644
+--- a/source/common/cpu.cpp
++++ b/source/common/cpu.cpp
+@@ -110,6 +110,11 @@ const cpu_name_t cpu_names[] =
+     { "", 0 },
+ };
+ 
++bool detect512()
++{
++    return(enable512);
++}
++
+ #if X265_ARCH_X86
+ 
+ extern "C" {
+@@ -123,10 +128,6 @@ uint64_t PFX(cpu_xgetbv)(int xcr);
+ #pragma warning(disable: 4309) // truncation of constant value
+ #endif
+ 
+-bool detect512()
+-{
+-    return(enable512);
+-}
+ uint32_t cpu_detect(bool benableavx512 )
+ {
+ 

x265.spec

@@ -19,6 +19,7 @@ Patch2:     x265-detect_cpu_armhfp.patch
 Patch3:     x265-arm-cflags.patch
 Patch4:     x265-pkgconfig_path_fix.patch
 Patch5:     x265-2.8-asm-primitives.patch
+Patch6:     https://sources.debian.org/data/main/x/x265/2.9-3/debian/patches/0003-detect512-is-needed-on-all-architectures.patch
 
 BuildRequires:  gcc-c++
 BuildRequires:  cmake3