RFR: 7903129: jextract does not handle @argfile

[Athijegannathan Sundararajan]

Missed CommandLine.parse call in JextractTool.run method.

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Commit messages:
 - 7903129: jextract does not handle @argfile

Changes: https://git.openjdk.java.net/jextract/pull/4/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jextract&pr=4&range=00
  Issue: https://bugs.openjdk.java.net/browse/CODETOOLS-7903129
  Stats: 13 lines in 2 files changed: 13 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jextract/pull/4.diff
  Fetch: git fetch https://git.openjdk.java.net/jextract pull/4/head:pull/4

PR: https://git.openjdk.java.net/jextract/pull/4