runtime: handle string + char literals in goc2c
runtime: handle string + char literals in goc2c

My string literal was being rewritten from
"runtime.SysReserve(%p, %D) = error %d"
to
"runtime.SysReserve ( %p , %D ) = error %d"

R=iant
CC=golang-dev
http://codereview.appspot.com/4972051

gnanderson/go,pombredanne/go-deleteme,dsriram/golang,gnanderson/go,pombredanne/go-deleteme,pombredanne/go-deleteme,gnanderson/go,dsriram/golang,tv42/old-go,apparentlymart/golang,gnanderson/go,tv42/old-go,dsriram/golang,tv42/old-go,pombredanne/go-deleteme,tv42/old-go,apparentlymart/golang,pombredanne/go-deleteme,tv42/old-go,tv42/old-go,apparentlymart/golang,gnanderson/go,apparentlymart/golang,dsriram/golang,apparentlymart/golang,dsriram/golang,tv42/old-go,apparentlymart/golang,pombredanne/go-deleteme,pombredanne/go-deleteme,gnanderson/go,dsriram/golang,apparentlymart/golang,dsriram/golang,gnanderson/go