x86/CET: Remove the -mcet command-lint option

With revision 259496:

commit b1384095a7
Author: hjl <hjl@138bc75d-0d04-0410-961f-82ee72b054a4>
Date:   Thu Apr 19 15:15:04 2018 +0000

    x86: Enable -fcf-protection with multi-byte NOPs

-fcf-protection no longer depens on -mcet and with revision 259522:

commit d59cfa9a40
Author: hjl <hjl@138bc75d-0d04-0410-961f-82ee72b054a4>
Date:   Fri Apr 20 13:30:13 2018 +0000

    Define __CET__ for -fcf-protection and remove -mibt

-mcet becomes an alias for -mshstk.  Since all usages of -mcet and
-mno-cet have either been removed or replaced, we can remove the -mcet
command-lint option.

	PR target/85485
	* common/config/i386/i386-common.c (ix86_handle_option): Don't
	handle OPT_mcet.
	* config/i386/i386.opt (mcet): Removed.
	* doc/install.texi: Remove -mcet documentation.
	* doc/invoke.texi: Likewise.

From-SVN: r259613

gcc/ChangeLog

@@ -1,3 +1,12 @@
+2018-04-24  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR target/85485
+	* common/config/i386/i386-common.c (ix86_handle_option): Don't
+	handle OPT_mcet.
+	* config/i386/i386.opt (mcet): Removed.
+	* doc/install.texi: Remove -mcet documentation.
+	* doc/invoke.texi: Likewise.
+
 2018-04-24  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR target/85485

gcc/common/config/i386/i386-common.c

@@ -543,7 +543,6 @@ ix86_handle_option (struct gcc_options *opts,
 	}
       return true;
 
-    case OPT_mcet:
     case OPT_mshstk:
       if (value)
 	{

gcc/config/i386/i386.opt

@@ -1006,11 +1006,6 @@ mgeneral-regs-only
 Target Report RejectNegative Mask(GENERAL_REGS_ONLY) Var(ix86_target_flags) Save
 Generate code which uses only the general registers.
 
-mcet
-Target Report Var(flag_cet) Init(0)
-Enable shadow stack built-in functions from Control-flow Enforcement
-Technology (CET).
-
 mshstk
 Target Report Mask(ISA_SHSTK) Var(ix86_isa_flags) Save
 Enable shadow stack built-in functions from Control-flow Enforcement

gcc/doc/install.texi

@@ -2107,7 +2107,7 @@ The option is disabled by default.  When @code{--enable-cet=auto}
 is used, it is enabled on Linux/x86 if target binutils
 supports @code{Intel CET} instructions and disabled otherwise.
 In this case the target libraries are configured to get additional
-@option{-fcf-protection} and @option{-mcet} options.
+@option{-fcf-protection} option.
 @end table
 
 @subheading Cross-Compiler-Specific Options

gcc/doc/invoke.texi

@@ -1261,7 +1261,7 @@ See RS/6000 and PowerPC Options.
 -msse4a  -m3dnow  -m3dnowa  -mpopcnt  -mabm  -mbmi  -mtbm  -mfma4  -mxop @gol
 -mlzcnt  -mbmi2  -mfxsr  -mxsave  -mxsaveopt  -mrtm  -mlwp  -mmpx  @gol
 -mmwaitx  -mclzero  -mpku  -mthreads -mgfni  -mvaes  @gol
--mcet -mshstk -mforce-indirect-call -mavx512vbmi2 @gol
+-mshstk -mforce-indirect-call -mavx512vbmi2 @gol
 -mvpclmulqdq -mavx512bitalg -mmovdiri -mmovdir64b -mavx512vpopcntdq @gol
 -mms-bitfields  -mno-align-stringops  -minline-all-stringops @gol
 -minline-stringops-dynamically  -mstringop-strategy=@var{alg} @gol
@@ -27300,9 +27300,6 @@ preferred alignment to @option{-mpreferred-stack-boundary=2}.
 @itemx -mpku
 @opindex mpku
 @need 200
-@itemx -mcet
-@opindex mcet
-@need 200
 @itemx -mavx512vbmi2
 @opindex mavx512vbmi2
 @need 200
@@ -27447,12 +27444,9 @@ This option enables use of the @code{movbe} instruction to implement
 @code{__builtin_bswap32} and @code{__builtin_bswap64}.
 
 @item -mshstk
-@itemx -mcet
 @opindex mshstk
-@opindex mcet
 The @option{-mshstk} option enables shadow stack built-in functions
-from x86 Control-flow Enforcement Technology (CET).  The @option{-mcet}
-option is an alias for the @option{-mshstk} option.
+from x86 Control-flow Enforcement Technology (CET).
 
 @item -mcrc32
 @opindex mcrc32