Revision r222473 causes following warning on alpha-linux-gnu when compiling pr34999.c:

/tmp/ccPdj6Kv.s: Assembler messages:
/tmp/ccPdj6Kv.s:107: Warning: nested .ent directives
/tmp/ccPdj6Kv.s:121: Warning: .end directive names different symbol than .ent
/tmp/ccPdj6Kv.s:124: Warning: .end directive without matching .ent

The failure can be seen with a crosscompiler to from x86_64-linux-gnu to alpha-linux-gnu with following command:

gcc-build-alpha/gcc/cc1 -O2 -freorder-blocks-and-partition -fprofile-use
-o pr34999.s -fpreprocessed pr34999.i

The resulting assembly shows nested .ent/.end directives where main.cold.0 was inserted:

--cut here--
        .set noreorder
        .set volatile
        .set noat
        .section        .rodata
$LC0:
        .string "test"
        .section        .text.unlikely,"ax",@progbits
        .align 2
$LCOLDB1:
        .section        .text.startup,"ax",@progbits
$LHOTB1:
        .align 2
        .align 4
        .globl main
        .ent main
main:
        .frame $15,32,$26,0
        .mask 0x4008000,-32
$LFB1:
        ldgp $29,0($27)
$main..ng:
        lda $30,-32($30)
$LCFI0:
        lda $1,$LC0
        lda $3,buf
        bis $31,$31,$31
        stq $15,8($30)
$LCFI1:
        mov $30,$15
$LCFI2:
        stq $26,0($30)
$LCFI3:
        .prologue 1
        lda $30,-48($30)
        stq $30,16($15)
        lda $6,4($1)
        ldq_u $4,4($1)
        ldq_u $5,0($1)
        ldq_u $2,3($1)
        bis $31,$31,$31
        extbl $4,$6,$8
        ldl $19,4($30)
        extll $5,$1,$0
        lda $24,$L2
        extlh $2,$1,$7
        insbl $8,0,$21
        bic $19,255,$20
        cpys $f31,$f31,$f31
        bis $0,$7,$16
        stl $16,0($30)
        bis $21,$20,$22
        stl $22,4($30)
        stq $24,8($3)
        lda $23,16($15)
        stq $30,16($3)
        bis $31,$31,$31
        stq $23,0($3)
        lda $3,4096($31)
        ldl $25,0($30)
        sll $25,40,$26
        sra $26,56,$27
        s4addq $27,30,$28
        bic $28,15,$1
        cmpult $1,$3,$5
        subq $30,$1,$2
        bne $5,$L7
        lda $6,-4096($30)
        bis $31,$31,$31
$L6:
        stq $31,0($6)
        lda $6,-8192($6)
        cmpule $6,$2,$4
        beq $4,$L6
        stq $31,0($2)
$L7:
        mov $2,$30
        mov $30,$16
        ble $27,$L9
        subl $27,1,$0
        zapnot $0,15,$7
        mov $31,$17
        s4addq $7,4,$18
        jsr $26,memset
        ldgp $29,0($26)
$L9:
        jsr $26,sub2
$L2:
        lda $15,-16($15)
        br $27,$LSJ100
$LSJ100:
        ldgp $29,0($27)
        ldq $16,16($15)
        lda $17,$LC0
        jsr $26,strcmp
        ldgp $29,0($26)
        bne $0,$L17
        mov $31,$16
        jsr $26,exit
$L17:
        br $31,$L4
        .section        .text.unlikely
        .ent main.cold.0
main.cold.0:
        .frame $15,32,$26,0
        .mask 0x4008000,-32
$L4:
$LCFI4:
        jsr $26,abort
$LFE1:
        .section        .text.startup
        bis $31,$31,$31
        .end main
        .section        .text.unlikely
        bis $31,$31,$31
        .end main.cold.0
$LCOLDE1:
        .section        .text.startup
$LHOTE1:
        .section        .text.unlikely
        .align 2
$LCOLDB2:
        .text
$LHOTB2:
        .align 2
        .align 4
        .globl sub2
        .ent sub2
sub2:
        .frame $15,16,$26,0
        .mask 0x4008000,-16
$LFB0:
        ldgp $29,0($27)
$sub2..ng:
        lda $30,-16($30)
$LCFI5:
        lda $1,buf
        stq $15,8($30)
$LCFI6:
        mov $30,$15
$LCFI7:
        stq $26,0($30)
$LCFI8:
        .prologue 1
        ldq $27,8($1)
        ldq $15,0($1)
        ldq $30,16($1)
        jmp $31,($27),0
$LFE0:
        .end sub2
        .section        .text.unlikely
$LCOLDE2:
        .text
$LHOTE2:
[...]
--cut here--