i386-common.c (processor_names): Add cascadelake.

i386-common.c (processor_names): Add cascadelake.

gcc/
      * common/config/i386/i386-common.c (processor_names): Add cascadelake.
      (processor_alias_table): Add cascadelake.
      * config.gcc: Add -march=cascadelake.
      * config/i386/i386-c.c (ix86_target_macros_internal): Handle cascadelake.
      * config/i386/i386.c (Add m_CASCADELAKE): New.
      (processor_cost_table): Add cascadelake.
      (get_builtin_code_for_version): Handle cascadelake.
      * config/i386/i386.h (TARGET_CASCADELAKE, PROCESSOR_CASCADELAKE): New.
      (PTA_CASCADELAKE): Ditto.
      * doc/invoke.texi: Add -march=cascadelake.

gcc/testsuite/
      * gcc.target/i386/funcspec-56.inc: Handle new march.

From-SVN: r267080