[Bug target/82927] New: [8 Regression] ICE in verify_flow_info building SH glibc

["jsm28 at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82927

            Bug ID: 82927
           Summary: [8 Regression] ICE in verify_flow_info building SH
                    glibc
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jsm28 at gcc dot gnu.org
                CC: hubicka at gcc dot gnu.org, marxin at gcc dot gnu.org
  Target Milestone: ---
            Target: sh4-linux-gnu

Created attachment 42570
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=42570&action=edit
preprocessed source

Given the fix for bug 82863 (checked in although that bug isn't yet closed),
GCC completes the libgcc build but then ICEs building glibc for sh4-linux-gnu. 
My expectation is that this ICE was also introduced by r254379, though I
haven't tested to verify this.  Compile the attached test (not reduced) with
-O2.

gconv_builtin.c: In function '__gconv_get_builtin_trans':
gconv_builtin.c:86:1: error: verify_flow_info: Wrong probability of edge 10->12
gconv_builtin.c:86:1: error: verify_flow_info: Wrong probability of edge 10->11
gconv_builtin.c:86:1: error: verify_flow_info: Wrong probability of edge 6->9
gconv_builtin.c:86:1: error: verify_flow_info: Wrong probability of edge 6->7
during RTL pass: expand
gconv_builtin.c:86:1: internal compiler error: verify_flow_info failed
0x71ba23 verify_flow_info()
        /scratch/jmyers/glibc/many8/src/gcc/gcc/cfghooks.c:265
0x10a9ef2 checking_verify_flow_info
        /scratch/jmyers/glibc/many8/src/gcc/gcc/cfghooks.h:198
0x10a9ef2 try_optimize_cfg
        /scratch/jmyers/glibc/many8/src/gcc/gcc/cfgcleanup.c:3015
0x10aa1fd cleanup_cfg(int)
        /scratch/jmyers/glibc/many8/src/gcc/gcc/cfgcleanup.c:3179
0x718815 execute
        /scratch/jmyers/glibc/many8/src/gcc/gcc/cfgexpand.c:6511
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