[PATCH 7/9] AArch64: precommit test for CMPBR instructions

Commit the test file `cmpbr.c` before rules for generating the new instructions are added, so that the changes in codegen are more obvious in the next commit. gcc/testsuite/ChangeLog: * lib/target-supports.exp: Add `cmpbr` to the list of extensions. * gcc.target/aarch64/cmpbr.c: N

[PATCH 7/9] AArch64: precommit test for CMPBR instructions

Commit the test file `cmpbr.c` before rules for generating the new instructions are added, so that the changes in codegen are more obvious in the next commit. gcc/testsuite/ChangeLog: * gcc.target/aarch64/cmpbr.c: New test. --- gcc/testsuite/gcc.target/aarch64/cmpbr.c | 1378