[Bug target/70738] New: Add -minteger-only option

[hjl.tools at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70738

            Bug ID: 70738
           Summary: Add -minteger-only option
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hjl.tools at gmail dot com
                CC: kirill.yukhin at intel dot com, ubizjak at gmail dot com
  Target Milestone: ---
            Target: x86

X86 Linux kernel is compiled only with integer instructions.  Currently,

-mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx -mno-80387 -mno-fp-ret-in-387 
-mskip-rax-setup 

is used to compile kernel.  If we add another non-integer feature, it
has to be turned off.  We can add a -minteger-only option to disable
all non-integer features so that kernel doesn't need a long list and
the same option will work for future compilers.