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

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