Is 'what' both relative adjective and relative pronoun?

The body was no longer twitching. The skin had taken on a milky bluish tinge. The corner of the mouth seemed to have stopped bleeding, and what little blood was still visible now appeared very slightly darker and thicker, although the red, green and amber bulbs of the footlights might be influencing my color perception.
[The Weed That Strings the Hangman's Bag]

There are two verbs after what-phrase. In this case, (1) is relative pronoun ‘that’ omitted after blood, or (2) does ‘what’ take two roles of a relative adjective and relative pronoun?

Solution 1:

The best classification of what in this usage is as a determiner:

what: determiner

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2. a. the (person, thing, persons, or things) that: we photographed what animals we could see

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Collins English Dictionary – Complete and Unabridged © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003

what little blood was still visible is a noun clause used here as subject; it may be paraphrased the small amount of blood that was still visible, or such traces of blood as were still visible. This what-structure does not take that.

Little is a quantifier here rather than the categorially polysemic adjective.

Solution 2:

What is here an adjective, meaning in the OED’s, definition 8, that (or those) . . . which (or who); such . . . as; often expressing quantity, So much (or many) . . .as.

One of eight citations illustrating the use is this, from John Ruskin: ‘I will take what indulgence the . . . reader will give me’.