build-lldb-mi: Sync cross compilation logic improvements from build-llvm.sh

build-lldb-mi.sh

@@ -100,20 +100,30 @@ if [ -n "$HOST" ]; then
     CMAKEFLAGS="$CMAKEFLAGS -DCMAKE_FIND_ROOT_PATH_MODE_PROGRAM=NEVER"
     CMAKEFLAGS="$CMAKEFLAGS -DCMAKE_FIND_ROOT_PATH_MODE_INCLUDE=ONLY"
     CMAKEFLAGS="$CMAKEFLAGS -DCMAKE_FIND_ROOT_PATH_MODE_LIBRARY=ONLY"
+    CMAKEFLAGS="$CMAKEFLAGS -DCMAKE_FIND_ROOT_PATH_MODE_PACKAGE=ONLY"
 fi
 
 if [ -n "$MACOS_REDIST" ]; then
     : ${MACOS_REDIST_ARCHS:=arm64 x86_64}
     : ${MACOS_REDIST_VERSION:=10.9}
     ARCH_LIST=""
+    NATIVE=
     for arch in $MACOS_REDIST_ARCHS; do
         if [ -n "$ARCH_LIST" ]; then
             ARCH_LIST="$ARCH_LIST;"
         fi
         ARCH_LIST="$ARCH_LIST$arch"
+        if [ "$(uname -m)" = "$arch" ]; then
+            NATIVE=1
+        fi
     done
     CMAKEFLAGS="$CMAKEFLAGS -DCMAKE_OSX_ARCHITECTURES=$ARCH_LIST"
     CMAKEFLAGS="$CMAKEFLAGS -DCMAKE_OSX_DEPLOYMENT_TARGET=$MACOS_REDIST_VERSION"
+    if [ -z "$NATIVE" ]; then
+        # If we're not building for the native arch, flag to CMake that we're
+        # cross compiling.
+        CMAKEFLAGS="$CMAKEFLAGS -DCMAKE_SYSTEM_NAME=Darwin"
+    fi
 fi
 
 cd lldb-mi