GeezerVison

This add hexadecimal floating point literals (IEEE 754-2008 §5.12.3) and
support construction of floats from hexadecimal strings.  Note that the
float constructor accepts more permissive syntax (everything that is
currently accepted by the float.fromhex, but with a mandatory base
specifier; it also allows grouping digits with underscores).

Examples:
```pycon
>>> 0x1.1p-1
0.53125
>>> float('0x1.1')
1.0625
>>> 0x1.1
  File "<stdin>", line 1
    0x1.1
        ^
SyntaxError: invalid floating point literal
```

Minor changes:
* Py_ISDIGIT/ISXDIGIT macros were transformed to functions
* cherry-picked sphinx workaround from python#108184

This add hexadecimal floating point literals (IEEE 754-2008 §5.12.3) and
support construction of floats from hexadecimal strings.  Note that the
float constructor accepts more permissive syntax (everything that is
currently accepted by the float.fromhex, but with a mandatory base
specifier; it also allows grouping digits with underscores).

Examples:
```pycon
>>> 0x1.1p-1
0.53125
>>> float('0x1.1')
1.0625
>>> 0x1.1
  File "<stdin>", line 1
    0x1.1
        ^
SyntaxError: invalid floating point literal
```

Minor changes:
* Py_ISDIGIT/ISXDIGIT macros were transformed to functions
* cherry-picked sphinx workaround from python#108184

(cherry picked from commit f3d5d4a)

Co-authored-by: William Andrea <[email protected]>
Co-authored-by: Adam Turner <[email protected]>
Co-authored-by: Sergey B Kirpichev <[email protected]>

(cherry picked from commit f3d5d4a)

Co-authored-by: William Andrea <[email protected]>
Co-authored-by: Adam Turner <[email protected]>
Co-authored-by: Sergey B Kirpichev <[email protected]>

…113840)

Docs: Link tokens in the format string grammars (GH-108184)
(cherry picked from commit f3d5d4a)

Co-authored-by: William Andrea <[email protected]>
Co-authored-by: Adam Turner <[email protected]>
Co-authored-by: Sergey B Kirpichev <[email protected]>

…113839)

Docs: Link tokens in the format string grammars (GH-108184)
(cherry picked from commit f3d5d4a)

Co-authored-by: William Andrea <[email protected]>
Co-authored-by: Adam Turner <[email protected]>
Co-authored-by: Sergey B Kirpichev <[email protected]>

This add hexadecimal floating point literals (IEEE 754-2008 §5.12.3) and
support construction of floats from hexadecimal strings.  Note that the
float constructor accepts more permissive syntax (everything that is
currently accepted by the float.fromhex, but with a mandatory base
specifier; it also allows grouping digits with underscores).

Examples:
```pycon
>>> 0x1.1p-1
0.53125
>>> float('0x1.1')
1.0625
>>> 0x1.1
  File "<stdin>", line 1
    0x1.1
        ^
SyntaxError: invalid floating point literal
```

Minor changes:
* Py_ISDIGIT/ISXDIGIT macros were transformed to functions
* cherry-picked sphinx workaround from python#108184

This add hexadecimal floating point literals (IEEE 754-2008 §5.12.3) and
support construction of floats from hexadecimal strings.  Note that the
float constructor accepts more permissive syntax (everything that is
currently accepted by the float.fromhex, but with a mandatory base
specifier; it also allows grouping digits with underscores).

Examples:
```pycon
>>> 0x1.1p-1
0.53125
>>> float('0x1.1')
1.0625
>>> 0x1.1
  File "<stdin>", line 1
    0x1.1
        ^
SyntaxError: invalid floating point literal
```

Minor changes:
* Py_ISDIGIT/ISXDIGIT macros were transformed to functions
* cherry-picked sphinx workaround from python#108184

This add hexadecimal floating point literals (IEEE 754-2008 §5.12.3) and
support construction of floats from hexadecimal strings.  Note that the
float constructor accepts more permissive syntax (everything that is
currently accepted by the float.fromhex, but with a mandatory base
specifier; it also allows grouping digits with underscores).

Examples:
```pycon
>>> 0x1.1p-1
0.53125
>>> float('0x1.1')
1.0625
>>> 0x1.1
  File "<stdin>", line 1
    0x1.1
        ^
SyntaxError: invalid floating point literal
```

Minor changes:
* Py_ISDIGIT/ISXDIGIT macros were transformed to functions
* cherry-picked sphinx workaround from python#108184

Co-authored-by: Adam Turner <[email protected]>
Co-authored-by: Sergey B Kirpichev <[email protected]>

Co-authored-by: Adam Turner <[email protected]>
Co-authored-by: Sergey B Kirpichev <[email protected]>

Co-authored-by: Adam Turner <[email protected]>
Co-authored-by: Sergey B Kirpichev <[email protected]>