add ARM64/Apple M1 support to build.sh (darktable-org#10178)

* add ARM64/Apple M1 support to build.sh

determines CPU architecture by `uname -a

build.sh

@@ -311,6 +311,21 @@ done
 CMAKE_PREFIX_PATH=${CMAKE_PREFIX_PATH:-}
 CMAKE_MORE_OPTIONS="${CMAKE_MORE_OPTIONS} ${CMAKE_PREFIX_PATH}"
 
+
+# ---------------------------------------------------------------------------
+# Determine CPU architecture
+# ---------------------------------------------------------------------------
+
+CPU_ARCHITECTURE=""
+if [[ `uname -a` =~ ^Darwin.* ]] && [[ `uname -a` =~ .*arm64$ ]]
+then
+    CPU_ARCHITECTURE="ARM64"
+    CMAKE_MORE_OPTIONS="${CMAKE_MORE_OPTIONS} -DBUILD_SSE2_CODEPATHS=OFF"
+else
+	CPU_ARCHITECTURE="Intel"
+fi
+
+
 # ---------------------------------------------------------------------------
 # Let's go
 # ---------------------------------------------------------------------------
@@ -323,6 +338,7 @@ Installation prefix: $INSTALL_PREFIX
 Build type:          $BUILD_TYPE
 Build generator:     $BUILD_GENERATOR
 Build tasks:         $MAKE_TASKS
+CPU Architecture:    $CPU_ARCHITECTURE
 
 EOF