malloc-h: New module.

* lib/malloc.in.h: New file.
* m4/malloc_h.m4: New file.
* modules/malloc-h: New file.
* doc/glibc-headers/malloc.texi: New file.
* doc/gnulib.texi (Glibc Header File Substitutes): Include it.

modules/malloc-h

@@ -0,0 +1,46 @@
+Description:
+A <malloc.h> that works around platform issues.
+
+Files:
+lib/malloc.in.h
+m4/malloc_h.m4
+
+Depends-on:
+include_next
+snippet/c++defs
+snippet/warn-on-use
+
+configure.ac:
+gl_MALLOC_H
+
+Makefile.am:
+BUILT_SOURCES += malloc.h
+
+# We need the following in order to create <malloc.h> when we add workarounds.
+malloc.h: malloc.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(WARN_ON_USE_H)
+	$(AM_V_GEN)rm -f $@-t $@ && \
+	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+	  sed -e 's|@''GUARD_PREFIX''@|${gl_include_guard_prefix}|g' \
+	      -e 's|@''HAVE_MALLOC_H''@|$(HAVE_MALLOC_H)|g' \
+	      -e 's|@''INCLUDE_NEXT''@|$(INCLUDE_NEXT)|g' \
+	      -e 's|@''PRAGMA_SYSTEM_HEADER''@|@PRAGMA_SYSTEM_HEADER@|g' \
+	      -e 's|@''PRAGMA_COLUMNS''@|@PRAGMA_COLUMNS@|g' \
+	      -e 's|@''NEXT_MALLOC_H''@|$(NEXT_MALLOC_H)|g' \
+	      -e 's/@''GNULIB_MEMALIGN''@/$(GNULIB_MEMALIGN)/g' \
+	      -e 's|@''HAVE_MEMALIGN''@|$(HAVE_MEMALIGN)|g' \
+	      -e 's|@''REPLACE_MEMALIGN''@|$(REPLACE_MEMALIGN)|g' \
+	      -e '/definitions of _GL_FUNCDECL_RPL/r $(CXXDEFS_H)' \
+	      -e '/definition of _GL_WARN_ON_USE/r $(WARN_ON_USE_H)' \
+	    < $(srcdir)/malloc.in.h; \
+	} > $@-t && \
+	mv $@-t $@
+MOSTLYCLEANFILES += malloc.h malloc.h-t
+
+Include:
+<malloc.h>
+
+License:
+LGPLv2+
+
+Maintainer:
+all