Rollup merge of #71964 - jcotton42:bootstrap_decode_none_windows, r=Mark-Simulacrum

Fix bootstrap failing on win32 ```powershell python x.py -h # or really any x.py command ``` would fail with ``` info: Downloading and building bootstrap before processing --help command. See src/bootstrap/README.md for help with common commands. Updating only changed submodules Submodules updated in 0.15 seconds Traceback (most recent call last): File "x.py", line 11, in <module> bootstrap.main() File "C:\Users\Joshua\Projects\forks\rust\src\bootstrap\bootstrap.py", line 960, in main bootstrap(help_triggered) File "C:\Users\Joshua\Projects\forks\rust\src\bootstrap\bootstrap.py", line 925, in bootstrap build.build = args.build or build.build_triple() File "C:\Users\Joshua\Projects\forks\rust\src\bootstrap\bootstrap.py", line 731, in build_triple return default_build_triple() File "C:\Users\Joshua\Projects\forks\rust\src\bootstrap\bootstrap.py", line 184, in default_build_triple ostype = require(["uname", "-s"], exit=required).decode(default_encoding) AttributeError: 'NoneType' object has no attribute 'decode' ``` This PR defers the `decode` call until after we're sure `ostype` and `cputype` are not `None`, as they would be on Windows since `uname` doesn't exist

Author: Dylan-DPC

src/bootstrap/bootstrap.py

@@ -180,12 +180,15 @@ def format_build_time(duration):
 def default_build_triple():
  """Build triple as in LLVM"""
  default_encoding = sys.getdefaultencoding()
- required = not sys.platform == 'win32'
- ostype = require(["uname", "-s"], exit=required).decode(default_encoding)
- cputype = require(['uname', '-m'], exit=required).decode(default_encoding)
+ required = sys.platform != 'win32'
+ ostype = require(["uname", "-s"], exit=required)
+ cputype = require(['uname', '-m'], exit=required)
 
  if ostype is None or cputype is None:
  return 'x86_64-pc-windows-msvc'
+ 
+ ostype = ostype.decode(default_encoding)
+ cputype = cputype.decode(default_encoding)
 
  # The goal here is to come up with the same triple as LLVM would,
  # at least for the subset of platforms we're willing to target.