[patch] move a call to assemble_external

[sje@cup.hp.com]

Rafael,

The patch didn't work for me.  I still fail to bootstrap.  Here is
a much smaller test case then David's.

	extern void foo();
	bar() { foo(); }

With the latest sources (and your patch), the only reference to foo
in the output is the branch statement:

	 bl foo,%r2

Using an older GCC I see the branch and an import statement:

        bl foo,%r2
        .IMPORT foo,CODE

Steve Ellcey
sje@cup.hp.com