make(1) vs spaces

[utzoo!henry]

If you have a makefile like this (the tab is written \t for clarity,
note the space preceding it):

	foo: foo.o
	 \tcc -n -s ...

make(1) will produce an EXTREMELY cryptic message.  It can take a long
time to track this one down, because the line LOOKS right.  Perhaps
make should consider spaces and tabs equivalent, but I am not sure this
is a good idea;  if it had been done that way from the beginning, ok,
but as a retrofit I wonder how many makefiles would break.  Failing
this, the error reporting definitely could stand some more smarts.