Fix classification of `module.type' in D lexer.

Fix classification of `module.type' in D lexer.

The two-tier lexer in gdb/d-exp.y, which resolves fully qualified names
missed a case where `module.type' was not being classified as one token.
And so when the grammar takes over, it matched the remaining tokens
against the rule `TypeExp . IdentifierExp', where we were expecting to
instead match cast expression `( TypeExp ) UnaryExpression'.

Adding a case for TYPE_CODE_MODULE in type_aggregate_p means that
classify_inner_name will get a chance to lookup the symbol.

This was noticed when using `watch -l', and got the rather confusing
response:

    A syntax error in expression, near `) 0x0add4e55'.

So it's been included in the testsuite, along with another test that
does effectively the same expression, but explicitly.

gdb/ChangeLog:

	* d-exp.y (type_aggregate_p): Treat TYPE_CODE_MODULE as being
	aggregate-like.

gdb/testsuite/ChangeLog:

	* gdb.dlang/watch-loc.c: New file.
	* gdb.dlang/watch-loc.exp: New file.