UP018 fix should add spaces between tokens

[dscorbett]

Summary

The fix for native-literals (UP018) should add spaces between tokens as necessary to avoid syntax errors and other problems.

Reverted syntax error:

$ cat >up018_1.py <<'# EOF'
bool(True)and None
# EOF

$ ruff --isolated check up018_1.py --select UP018 --diff 2>&1 | grep error:
error: Fix introduced a syntax error. Reverting all changes.

Runtime SyntaxWarnings:

$ cat >up018_2.py <<'# EOF'
int(1)and None
float(1.)and None
# EOF

$ ruff --isolated check up018_2.py --select UP018 --fix
Found 2 errors (2 fixed, 0 remaining).

$ cat up018_2.py
1and None
1.and None

$ python up018_2.py
up018_2.py:1: SyntaxWarning: invalid decimal literal
  1and None
up018_2.py:2: SyntaxWarning: invalid decimal literal
  1.and None

Runtime behavior change:

$ cat >up018_3.py <<'# EOF'
bool(True)and()
# EOF

$ ruff --isolated check up018_3.py --select UP018 --fix
Found 1 error (1 fixed, 0 remaining).

$ cat up018_3.py
Trueand()

$ python up018_3.py 
Traceback (most recent call last):
  File "up018_3.py", line 1, in <module>
    Trueand()
    ^^^^^^^
NameError: name 'Trueand' is not defined

Version

ruff 0.11.6 (fcd50a0 2025-04-17)