make check failed for builtins testcases when lto enabled

[Amker.Cheng]

Hi,
I noticed there are some builtins testcases failed in my "make
check-gcc" when lto enabled.
the command line like:

xgcc ...
.../gcc/testsuite/gcc.c-torture/execute/builtins/strlen.c
.../gcc/testsuite/gcc.c-torture/execute/builtins/strlen-lib.c
.../gcc/testsuite/gcc.c-torture/execute/builtins/lib/main.c
-w -O2
-flto -flto-partition=none
-lm -specs=rdimon.specs -lrdimon -lc -lg -lrdimon -mthumb -mcpu=cortex-m3
-o .../gcc/testsuite/gcc/strlen.x6

this failed testcase always complains:
/tmp/ccw8n1Wt.lto.o: In function `strlen':
ccYaDFzm.o:(.text+0x0): multiple definition of `strlen'
.../lib/gcc/arm-none-eabi/4.7.0/../../../../arm-none-eabi/lib/armv7-m/libc.a(lib_a-strlen.o):strlen.c:(.text+0x0):
first defined here
collect2: error: ld returned 1 exit status

There are a copy of strlen in c source file and a copy in libc.a.
Seems gcc/lto always link libc.a and find the library copy first,
which results in re-definition error.

So any suggestions? Thanks very much.

BTW, the testcase is ok without"-flto -flto-partition=none" specified.

-- 
Best Regards.