reverse continue, watch break not triggered as expected

I reported the following as:
https://sourceware.org/bugzilla/show_bug.cgi?id=21969

I thought I should check with the list to see if I might just be missing
something.  Any thoughts would be most appreciated.

utl1.c : test program with deliberate stack overwrite
int main()
{
    int a[10],i;
    for(i=0;i<20;i++)
    {
       a[i]=i;
    }
}

OS          : Linux DellXPS 4.10.0 #1 SMP Thu Apr 13 09:55:54 EDT 2017 
x86_64 GNU/Linux
gdb version : 8.0

build utl1.c as follows:
gcc -Wall -Wno-unused-but-set-variable -g utl1.c -o0 -o utl1

After the forward continue, the watch break is triggered as expected :

gdb utl1
C-x 2      # ctrl-x 2
b *main    # break on 1st main() instruction
run
record
watch -l *((long *)$sp)
continue


After the reverse continue, the watch break is not triggered as expected :

gdb utl1
C-x 2      # ctrl-x 2
b *main    # break on 1st main() instruction
b *main+41 # break on retq instruction
run
record
continue
watch -l *((long *)$sp)
reverse-continue