Allow building a redistributable package for macOS

This includes building universal binaries (for arm64 and x86_64)
and targeting an older minimum deployment target.

(Before 1919720fdd348ca568b235bf3f1357c198eccd15 in llvm-project,
Jan 2022, building lldb's debugserver failed, if building for macOS
for multiple architectures, or for an architecture other than the
current host.)

build-lldb-mi.sh

@@ -103,6 +103,11 @@ if [ -n "$HOST" ]; then
     CMAKEFLAGS="$CMAKEFLAGS -DCMAKE_FIND_ROOT_PATH_MODE_LIBRARY=ONLY"
 fi
 
+if [ -n "$MACOS_REDIST" ]; then
+    CMAKEFLAGS="$CMAKEFLAGS -DCMAKE_OSX_ARCHITECTURES=arm64;x86_64"
+    CMAKEFLAGS="$CMAKEFLAGS -DCMAKE_OSX_DEPLOYMENT_TARGET=10.9"
+fi
+
 cd lldb-mi
 
 [ -z "$CLEAN" ] || rm -rf $BUILDDIR

build-llvm.sh

@@ -194,6 +194,11 @@ if [ -n "$LTO" ]; then
     CMAKEFLAGS="$CMAKEFLAGS -DLLVM_ENABLE_LTO=$LTO"
 fi
 
+if [ -n "$MACOS_REDIST" ]; then
+    CMAKEFLAGS="$CMAKEFLAGS -DCMAKE_OSX_ARCHITECTURES=arm64;x86_64"
+    CMAKEFLAGS="$CMAKEFLAGS -DCMAKE_OSX_DEPLOYMENT_TARGET=10.9"
+fi
+
 TOOLCHAIN_ONLY=ON
 if [ -n "$FULL_LLVM" ]; then
     TOOLCHAIN_ONLY=OFF

build-mingw-w64-tools.sh

@@ -72,6 +72,12 @@ else
         ;;
     esac
 fi
+if [ -n "$MACOS_REDIST" ]; then
+    if [ -z "$CFLAGS" ]; then
+        export CFLAGS="-g -O2"
+    fi
+    export CFLAGS="$CFLAGS -arch arm64 -arch x86_64 -mmacosx-version-min=10.9"
+fi
 if [ -n "$SKIP_INCLUDE_TRIPLET_PREFIX" ]; then
     INCLUDEDIR="$PREFIX/include"
 else

install-wrappers.sh

@@ -54,6 +54,10 @@ if [ -n "$HOST" ]; then
     EXEEXT=.exe
 fi
 
+if [ -n "$MACOS_REDIST" ]; then
+    WRAPPER_FLAGS="$WRAPPER_FLAGS -arch arm64 -arch x86_64 -mmacosx-version-min=10.9"
+fi
+
 if [ -n "$EXEEXT" ]; then
     CLANG_MAJOR=$(basename $(echo $PREFIX/lib/clang/* | awk '{print $NF}') | cut -f 1 -d .)
     WRAPPER_FLAGS="$WRAPPER_FLAGS -municode -DCLANG=\"clang-$CLANG_MAJOR\""