(maint) support building pdk and bolt runtimes on osx arm64

configs/projects/bolt-runtime.rb

@@ -85,14 +85,17 @@
   end
 
   if platform.is_macos?
-    # For OS X, we should optimize for an older architecture than Apple
+    proj.setting(:cppflags, "-I#{proj.includedir}")
+    proj.setting(:cflags, proj.cppflags.to_s)
+
+    # For OS X, we should optimize for an older x86 architecture than Apple
     # currently ships for; there's a lot of older xeon chips based on
     # that architecture still in use throughout the Mac ecosystem.
     # Additionally, OS X doesn't use RPATH for linking. We shouldn't
     # define it or try to force it in the linker, because this might
     # break gcc or clang if they try to use the RPATH values we forced.
-    proj.setting(:cppflags, "-I#{proj.includedir}")
-    proj.setting(:cflags, "-march=core2 -msse4 #{proj.cppflags}")
+    proj.setting(:cflags, "-march=core2 -msse4 #{proj.cflags}") unless platform.architecture == 'arm64'
+
     proj.setting(:ldflags, "-L#{proj.libdir} ")
   end
 

configs/projects/pdk-runtime.rb

@@ -128,11 +128,12 @@
     proj.setting(:ldflags, "-L#{proj.tools_root}/lib -L#{proj.gcc_root}/lib -L#{proj.libdir}")
   elsif platform.is_macos?
     proj.setting(:cppflags, "-I#{proj.includedir}")
+    proj.setting(:cflags, "#{proj.cppflags}")
 
     # Since we are cross-compiling for later use, we can only optimize for
     # the oldest supported platform and even up to macOS 10.13 there are
     # a few Core 2 hardware platforms supported. (4 May 2018)
-    proj.setting(:cflags, "-march=core2 -msse4 #{proj.cppflags}")
+    proj.setting(:cflags, "-march=core2 -msse4 #{proj.cflags}") unless platform.architecture == 'arm64'
 
     # OS X doesn't use RPATH for linking. We shouldn't
     # define it or try to force it in the linker, because this might