Fixing ecma_zt_string_to_number for '-0' string.
Fixing ecma_zt_string_to_number for '-0' string.

grgustaf/jerryscript,jerryscript-project/jerryscript,yichoi/jerryscript,bzsolt/jerryscript,LeeHayun/jerryscript,robertsipka/jerryscript,zherczeg/jerryscript,dbatyai/jerryscript,glistening/jerryscript,slaff/jerryscript,dbatyai/jerryscript,slaff/jerryscript,LaszloLango/jerryscript,yichoi/jerryscript,martijnthe/jerryscript,bsdelf/jerryscript,jack60504/jerryscript,loki04/jerryscript,dbatyai/jerryscript,gabrielschulhof/jerryscript,akosthekiss/jerryscript,slaff/jerryscript,robertsipka/jerryscript,grgustaf/jerryscript,LaszloLango/jerryscript,zherczeg/jerryscript,LaszloLango/jerryscript,loki04/jerryscript,robertsipka/jerryscript,bzsolt/jerryscript,martijnthe/jerryscript,martijnthe/jerryscript,bsdelf/jerryscript,dbatyai/jerryscript,robertsipka/jerryscript,grgustaf/jerryscript,glistening/jerryscript,LeeHayun/jerryscript,akosthekiss/jerryscript,bsdelf/jerryscript,jerryscript-project/jerryscript,loki04/jerryscript,bsdelf/jerryscript,LeeHayun/jerryscript,bzsolt/jerryscript,glistening/jerryscript,yichoi/jerryscript,bsdelf/jerryscript,LaszloLango/jerryscript,gabrielschulhof/jerryscript,bsdelf/jerryscript,glistening/jerryscript,jack60504/jerryscript,loki04/jerryscript,martijnthe/jerryscript,akosthekiss/jerryscript,tilmannOSG/jerryscript,gabrielschulhof/jerryscript,tilmannOSG/jerryscript,jerryscript-project/jerryscript,martijnthe/jerryscript,grgustaf/jerryscript,gabrielschulhof/jerryscript,robertsipka/jerryscript,grgustaf/jerryscript,tilmannOSG/jerryscript,LeeHayun/jerryscript,jerryscript-project/jerryscript,yichoi/jerryscript,loki04/jerryscript,dbatyai/jerryscript,akosthekiss/jerryscript,gabrielschulhof/jerryscript,martijnthe/jerryscript,zherczeg/jerryscript,bzsolt/jerryscript,akosthekiss/jerryscript,glistening/jerryscript,LeeHayun/jerryscript,jack60504/jerryscript,grgustaf/jerryscript,robertsipka/jerryscript,LaszloLango/jerryscript,slaff/jerryscript,zherczeg/jerryscript,tilmannOSG/jerryscript,yichoi/jerryscript,zherczeg/jerryscript,bzsolt/jerryscript,jack60504/jerryscript,jack60504/jerryscript,loki04/jerryscript,glistening/jerryscript,jack60504/jerryscript,slaff/jerryscript,tilmannOSG/jerryscript,jerryscript-project/jerryscript