Add glob package for pattern matching

[bobzhang]

This PR adds a comprehensive glob pattern matching package to the MoonBit standard library.

Features

• Wildcards: * (zero or more chars), ? (exactly one char)
• Character classes: [abc], [a-z], [!abc], [^abc]
• Brace expansion: {a,b,c}
• Recursive patterns: ** (matches across directories)
• Escape sequences: \ to escape special characters

Implementation

• Clean, efficient recursive backtracking implementation
• Proper handling of path separators (/)
• Full Unicode support via Int::unsafe_to_char

Testing

• 150+ test cases covering:

  • All wildcard and pattern features
  • Character classes and negation
  • Brace expansion with wildcards
  • Recursive ** patterns
  • Edge cases and error conditions
  • Real-world use cases (gitignore patterns, file matching)

• All tests passing: 5572/5572

• Zero warnings after moon check

Documentation

Includes comprehensive README.mbt.md with:

• Feature overview
• Usage examples for each pattern type
• Real-world examples
• API reference
• Performance notes

Examples

@glob.is_match("*.txt", "hello.txt")                    // true
@glob.is_match("file[0-9].log", "file5.log")            // true
@glob.is_match("{jpg,png,gif}", "photo.jpg")            // true
@glob.is_match("**/*.rs", "src/lib/mod.rs")             // true
@glob.is_match("src/**/test/*.txt", "src/a/b/test/x.txt") // true

[coveralls]

Pull Request Test Coverage Report for Build 1867

Details

• 68 of 76 (89.47%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.01%) to 91.559%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
glob/glob.mbt	68	76	89.47%

Totals
Change from base Build 1862:	-0.01%
Covered Lines:	10359
Relevant Lines:	11314

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💛 - Coveralls