Integrated: 8251027: DrawString with TexturePaint is corrupted

[Jayathirth D V]

In MaskFill wrong maskscan was used. Made changes to use appropriate maskscan value and did cleanup to remove unused
arguments of MTLVertexCache_AddMaskQuad.

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Commit messages:
 - 8251027: DrawString with TexturePaint is corrupted

Changes: https://git.openjdk.java.net/lanai/pull/83/files
 Webrev: https://webrevs.openjdk.java.net/lanai/83/webrev.00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8251027
  Stats: 12 lines in 4 files changed: 0 ins; 4 del; 8 mod
  Patch: https://git.openjdk.java.net/lanai/pull/83.diff
  Fetch: git fetch https://git.openjdk.java.net/lanai pull/83/head:pull/83

PR: https://git.openjdk.java.net/lanai/pull/83