new problem on i386-netbsd1.3H with process.S

[Ken Raeburn]

In lwp/process.S version 1.22, the "savecontext" symbol is defined
instead of "_savecontext", and similarly for "returnto", because it's
picking up these definitions from <machine/asm.h>:

    #ifdef __STDC__
    # define _C_LABEL(x)    _ ## x
    #else
    # define _C_LABEL(x)    _/**/x
    #endif
    #define _ENTRY(x) \
	    .text; _ALIGN_TEXT; .globl x; .type x, at function; x:
    #define ENTRY(y)        _ENTRY(_C_LABEL(y)); _PROF_PROLOGUE
    #define NENTRY(y)       _ENTRY(_C_LABEL(y))

instead of the ones provided in process.S, which behave differently.
This causes the test link to fail, and all the other attempts to
produce process.o fail as well.

Version 1.21 used ENTRY(savecontext) instead of _ENTRY(savecontext),
and that appears to be more correct when using these system macros.

Ken