Build lib/e-*.o only on platforms that need it

Build lib/e-*.o only on platforms that need it

* configure.ac (hybrid malloc): Simplify configuration.
(SHEAP_OBJ): Remove; no longer needed.
(HYBRID_MALLOC): New var. Subst it.
(HYBRID_MALLOC_LIB): New Automake conditional.
* lib/Makefile.am (noinst_LIBRARIES): Add libegnu.a only if
HYBRID_MALLOC_LIB.
(libegnu_a_CPPFLAGS): Omit AM_CPPFLAGS; not needed.
(MOSTLYCLEANFILES): Add libegnu.a.
* src/Makefile.in (SHEAP_OBJ): Remove.
(HYBRID_MALLOC): New macro.
(base_obj): Use it to conditionally add sheap.o.
(LIBEGNU_ARCHIVE): New macro.
($(LIBEGNU_ARCHIVE)): New rule, replacing $(lib)/libegnu.a.
All uses of the latter replaced by the former.
* src/alloc.c (USE_ALIGNED_ALLOC): Simplify configuration.
Correct misspelling ALIGNED_ALLOC to HAVE_ALIGNED_ALLOC.
* src/gmalloc.c: Update comment.
* src/lisp.h (aligned_alloc)
[!DOUG_LEA_MALLOC && !HYBRID_MALLOC && !SYSTEM_MALLOC]:
New decl.
(Bug#22086)