[Bug target/63890] [4.9/5.0 regression] Compiling trivial program with -O -p leads to misaligned stack

[iains at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63890

--- Comment #5 from Iain Sandoe <iains at gcc dot gnu.org> ---

recent trunk on linux -m32 -O -p doesn't segv 
- but the stack looks odd at the mcount call.

    .file    "t.c"
    .text
    .globl    main
    .type    main, @function
main:
.LFB0:
    .cfi_startproc
    leal    4(%esp), %ecx
    .cfi_def_cfa 1, 0
    andl    $-16, %esp
    pushl    -4(%ecx)
    pushl    %ebp
    .cfi_escape 0x10,0x5,0x2,0x75,0
    movl    %esp, %ebp
    pushl    %ecx
    .cfi_escape 0xf,0x3,0x75,0x7c,0x6
    subl    $16, %esp
1:    call    mcount
    pushl    $0
    call    exit
    .cfi_endproc
.LFE0:
    .size    main, .-main
    .ident    "GCC: (GNU) 5.0.0 20141112 (experimental) [trunk revision
217427]"
    .section    .note.GNU-stack,"",@progbits