build: fix errors with pointer compression

[sapics]

This PR would fix the issue #54531 which reports build error in linux with pointer-compression.
#54531 reports that the PR #53884 code causes the error.
#53884 was fixed the error reported in #51339.

In #51339, the error is reported in macOS, therefore, I make to be v8_enable_sandbox=1 only if OS is macOS.

I am not good at English and python and clang, if there are anything wrong, please notice me.

[mhdawson]

I don't quite understand how this fixes the issue. It seems to just not enable except on Mac. From my quick read of the related issues I'm not sure how not enabling on linux but enabling on Mac makes sense.

@sapics can you explain a bit more as to why this is the right fix?

[sapics]

Thanks for your attension!
Sorry for the lack of explanation.

The reason for disabling except Mac

• Before build: ensure v8_pointer_compression_sandbox is enabled on 64bit #53884 merged

  • The build with pointer-compression was failed in MacOS (reported in --experimental-enable-pointer-compression causes build failure #51339)
  • The build with pointer-compression was succeeded in Linux (https://ci.nodejs.org/job/node-test-commit-linux-pointer-compression/294/)

• After build: ensure v8_pointer_compression_sandbox is enabled on 64bit #53884 merged

  • The build with pointer-compression might be succeeded in MacOS, I guess. (Not confirmed, but the build: ensure v8_pointer_compression_sandbox is enabled on 64bit #53884 author is the same author of --experimental-enable-pointer-compression causes build failure #51339)
  • The build with pointer-compression was failed in Linux

In #53884 (0c2aa7d), it changes

+ o['variables']['v8_enable_sandbox'] = 1 if options.enable_pointer_compression else 0

I changed as follows from the assumption that #53884 was probably effective on MacOS.

- o['variables']['v8_enable_sandbox'] = 1 if options.enable_pointer_compression else 0
+ o['variables']['v8_enable_sandbox'] = 1 if options.enable_pointer_compression and flavor == 'mac' else 0

The other way

I have confirmed only in Linux, thus, I cannot judge if v8_enable_sandbox=1 is good for the other OS.

If the #51339 have not solved by #53884 merged, it might be better to fix

- o['variables']['v8_enable_sandbox'] = 1 if options.enable_pointer_compression else 0

or

- o['variables']['v8_enable_sandbox'] = 1 if options.enable_pointer_compression else 0
+ o['variables']['v8_enable_sandbox'] = 1 if options.enable_pointer_compression and flavor != 'linux' else 0

[sapics]

Sorry, I close this PR, because I am not a specialist of this work.