Description:
------------
1. -O0 of gcc will be used to compile the math.c when enable debug,
and lead to the below error

aarch64-wrs-linux-gcc --sysroot=/buildarea1/lirq/wrlinux-8.0/a64/bitbake_build/tmp/sysroots/qemuarm64 -DPHP_ATOM_INC -D_REENTRANT  -pipe -g -D_GNU_SOURCE -g -DPTYS_ARE_GETPT -DPTYS_ARE_SEARCHED -O0 -Wall -DZTS -c /buildarea1/lirq/wrlinux-8.0/a64/bitbake_build/tmp/work/aarch64-wrs-linux/php/5.5.26-r0/php-5.5.26/ext/standard/math.c  -fPIC -DPIC -o ext/standard/.libs/math.o

| {standard input}: Assembler messages:
| {standard input}:2977: Error: operand 2 should be an integer register -- `mul x1,[x29,200],[x29,192]'
| {standard input}:2978: Error: operand 2 should be an integer register -- `smulh x0,[x29,200],[x29,192]'
| {standard input}:3042: Error: operand 2 should be an integer register -- `mul x1,[x29,192],[x29,192]'
| {standard input}:3043: Error: operand 2 should be an integer register -- `smulh x0,[x29,192],[x29,192]'


2. if -O2 of gcc is used, not this building failure. 

Expected result:
----------------
pass the building on aarch64 when enable debug