:r in adb drops arg chars in 4.2

[rws at mit-bold]

From:  Robert W. Scheifler <rws at mit-bold>

Description:
	When using adb,
		:r foo bar foobar bletch
	ends up passing "foo ar oobar letch" as arguments.
Repeat-By:
	adb /bin/echo
	:r foo bar bletch
Fix:
	In runpcs.c, in doexec(), change the loop
		REP	IF rdc()==EOR THEN break; FI
			...
			WHILE lastc==SP ORF lastc==TB DO readchar(); OD
		PER lastc!=EOR DONE
	to be
		readchar();
		LOOP
			WHILE lastc==SP ORF lastc==TB DO readchar(); OD
			IF lastc==EOR THEN break; FI
			...
		POOL