Defer minimal symbol name-setting

Defer minimal symbol name-setting

Currently the demangled name of a minimal symbol is set when creating
the symbol.  However, there is no intrinsic need to do this.  This
patch instead arranges for the demangling to be done just before the
minsym hash tables are filled.  This will be useful in a later patch.

gdb/ChangeLog
2019-10-19  Tom Tromey  <tom@tromey.com>

	* symtab.h (struct minimal_symbol) <name_set>: New member.
	* minsyms.c (minimal_symbol_reader::record_full): Copy name.
	Don't call symbol_set_names.
	(minimal_symbol_reader::install): Call symbol_set_names.

Change-Id: I4fe3993b99fb3a43968067806e294d48e377fd76