Further cleanup of macOS build setup

I don't think we need force_cpusubtype_ALL at this point or stdlib; CMake
build runs into the same problem with stdlib flag as make so it's easier
to just remove it.

We do need macOS version setting, both to ensure a reasonable binary target,
and because we use an API that's deprecated in macOS 13.

CMakeLists.txt

@@ -40,14 +40,10 @@ else()
 
     if (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
         add_compile_options(
-            -force_cpusubtype_ALL
             -mmacosx-version-min=10.7
-            -stdlib=libc++
         )
         add_link_options(
-            -force_cpusubtype_ALL
             -mmacosx-version-min=10.7
-            -stdlib=libc++
             "SHELL:-framework CoreFoundation"
             "SHELL:-framework CoreServices"
         )

Makefile

@@ -16,8 +16,7 @@ CCFLAGS+=-DUSE_NEON
 endif
 
 ifeq ($(shell uname),Darwin)
-CCFLAGS+=-force_cpusubtype_ALL -mmacosx-version-min=10.7
-CXXFLAGS+=-stdlib=libc++
+CCFLAGS+=-mmacosx-version-min=10.7
 LDFLAGS+=-mmacosx-version-min=10.7
 LDFLAGS+=-framework CoreFoundation -framework CoreServices
 else