Testsuite: Update CRC dump scan regex for reversed crc table
Updates testsuite regexes to match the new "emitting reversed crc table" message in CRC table dumps.
The middle-end optimization that builds reversed CRC tables directly changed the dump message. This commit updates the testsuite regexes to match the new message, preventing test failures on targets without a crc_rev optab (e.g., x86 without SSE4.2). This ensures that the testsuite continues to function correctly after the CRC table optimization.
In Details
Commit r17-567 changed the output of CRC table dumps when a reversed CRC table is built directly (i.e., without using a crc_rev optab). The testsuite expected "emitting crc table", but the new message is "emitting reversed crc table". This commit updates the regexes in gcc.dg/crc-builtin-rev-target*.c to match the new output, specifically for targets like x86 without TARGET_CRC32.
For Context
Cyclic Redundancy Check (CRC) is an error-detecting code commonly used in digital networks and storage devices. The compiler generates CRC tables to speed up CRC calculations. The testsuite verifies the correctness of these tables by examining the compiler's output (dumps). This commit updates the tests to account for a recent change in how the compiler describes reversed CRC tables in its output, thus preventing false test failures.