Initial Panther Lake Support

Initial Panther Lake Support

gcc/ChangeLog:

	* common/config/i386/cpuinfo.h (get_intel_cpu): Add Panther
	Lake.
	* common/config/i386/i386-common.cc (processor_name):
	Ditto.
	(processor_alias_table): Ditto.
	* common/config/i386/i386-cpuinfo.h (enum processor_types):
	Add INTEL_PANTHERLAKE.
	* config.gcc: Add -march=pantherlake.
	* config/i386/driver-i386.cc (host_detect_local_cpu): Refactor
	the if clause. Handle pantherlake.
	* config/i386/i386-c.cc (ix86_target_macros_internal):
	Handle pantherlake.
	* config/i386/i386-options.cc (processor_cost_table): Ditto.
	(m_PANTHERLAKE): New.
	(m_CORE_HYBRID): Add pantherlake.
	* config/i386/i386.h (enum processor_type): Ditto.
	* doc/extend.texi: Ditto.
	* doc/invoke.texi: Ditto.

gcc/testsuite/ChangeLog:

	* g++.target/i386/mv16.C: Ditto.
	* gcc.target/i386/funcspec-56.inc: Handle new march.