Change IA MCU processor from iamcu to lakemount

Change IA MCU processor from iamcu to lakemount

The first IA MCU processor will be Lakemount.  This patch changes IA MCU
processor name from iamcu to lakemount.

gcc/

	* config.gcc (x86_archs): Replace iamcu with lakemount.
	(with_cpu): Likewise.
	(with_arch): Likewise.
	* doc/invoke.texi: Likewise.
	* config/i386/i386-c.c (ix86_target_macros_internal): Replace
	PROCESSOR_IAMCU with PROCESSOR_LAKEMOUNT.  Replace
	__tune_iamcu__ with __tune_lakemount__.
	* config/i386/i386.c (iamcu_cost): Renamed to ...
	(lakemount_cost): This.
	(m_IAMCU): Renamed to ...
	(m_LAKEMOUNT): This.
	(initial_ix86_arch_features): Replace m_IAMCU with m_LAKEMOUNT.
	(processor_target_table): Replace "iamcu" with "lakemount".
	(processor_alias_table): Likewise.
	(ix86_issue_rate): Replace PROCESSOR_IAMCU with
	PROCESSOR_LAKEMOUNT.
	(ix86_adjust_cost): Likewise.
	(ia32_multipass_dfa_lookahead): Likewise.
	* config/i386/i386.h (processor_type): Likewise.
	* config/i386/x86-tune.def: Replace m_IAMCU with m_LAKEMOUNT.

gcc/testsuite/

	* gcc.target/i386/pr66749.c (dg-options): Replace -mtune=iamcu
	with -mtune=lakemount.
	* gcc.target/i386/pr66821.c (dg-options): Likewise.
	* gcc.target/i386/pr67329.c (dg-options): Likewise.

From-SVN: r228109