[php-src] PR #24353: ext/pdo_pgsql: Speed up the SQL scanner

Pull Request: https://github.com/php/php-src/pull/24353 Author: brainexe The pgsql placeholder scanner excluded e/E from plain text because they can start an E'...' string. As a result, every e/E in a query (SELECT, WHERE, created_at, …) ended the current text token and became a one-character token of its own. This PR: - allows e/E inside text runs as long as a run doesn't end with one, so E'...' strings are still recognized exactly as before - generates the scanner with re2c bitmaps (-b) instead of a switch on every input character The scanner runs in PDO::prepare() and, with emulated prepares, again in PDOStatement::execute(). ## Benchmark Instructions (perf stat -e instructions:u, mean of 5 runs) for 200k PDO::prepare() calls, compared to master: | Query | Emulated prepares | Native prepares | |---|---|---| | SELECT with 11 columns, 2 named params | −24% | −16% | | INSERT with 8 named params | −15% | −7% | For a whole emulated query (prepare, execute, fetch one row) against a local PostgreSQL server, PHP executes 7–9% fewer instructions. ## Verification - New test ext/pdo_pgsql/tests/pdo_pgsql_parser_e_strings.phpt, run with both emulated and native prepares. It covers E'...' strings directly after text, ESCAPE'!', date'...', placeholders after E'...' strings and words ending in e/E. - Differential fuzzing against master: ~13k random queries built from SQL fragments (quotes, E'...' strings, dollar quotes, comments, ??, named and positional placeholders), each executed with 8 binding variants. The rewritten SQL and the errors were identical. - Built with scanners generated by re2c 4.4 and re2c 1.3, the configure minimum being 1.0.3. - ext/pdo and ext/pdo_pgsql test suites pass with native prepares. With emulated prepares forced on (PDO_PGSQL_TEST_ATTR), the same tests fail as on master.