Decompression implementation improvement ideas

[pfalcon]

• Distance tree can have only 30 valid codes (32 total if balanced Huffman tree is considered). That's unlike literal/length tree which can 286 valid, 288 total entries. Using the same structure for both types of trees, reserving space for 288 codes is thus not efficient. Using adhoc structure for distance tree can provide noticeable space savings.

[pfalcon]

4c50ea3 proposes to de-inline TINF_PUT. While definitely beneficial for code size, performance impact should be assessed.