<uncomment> system code macos in terralib.lua

src/terralib.lua

@@ -3774,11 +3774,11 @@ function terra.includecstring(code,cargs,target)
     	args:insert(path)
     end
     -- Obey the SDKROOT variable on macOS to match Clang behavior.
-    --local sdkroot = os.getenv("SDKROOT")
-    --if sdkroot then
-    --  args:insert("-isysroot")
-    --  args:insert(sdkroot)
-    --end
+    local sdkroot = os.getenv("SDKROOT")
+    if sdkroot then
+      args:insert("-isysroot")
+      args:insert(sdkroot)
+    end
     -- Set GNU C version to match value set by Clang: https://github.com/llvm/llvm-project/blob/f77c948d56b09b839262e258af5c6ad701e5b168/clang/lib/Driver/ToolChains/Clang.cpp#L5750-L5753
     if ffi.os ~= "Windows" and terralib.llvm_version >= 100 then
       args:insert("-fgnuc-version=4.2.1")