RFR: 8262276: Debug build of WebKit fails [v2]

[Arun Joseph]

> Fixing the Debug build of WebKit.
> 
> Test: Build JavaFX using `-PCOMPILE_WEBKIT=true -PCONF=DebugNative` and test using a simple HelloWebView app.

Arun Joseph has updated the pull request incrementally with one additional commit since the last revision:

  Fix InternalFunction crash

-------------

Changes:
  - all: https://git.openjdk.java.net/jfx/pull/417/files
  - new: https://git.openjdk.java.net/jfx/pull/417/files/6cab829e..31ea28c0

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jfx&pr=417&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jfx&pr=417&range=00-01

  Stats: 10 lines in 1 file changed: 0 ins; 0 del; 10 mod
  Patch: https://git.openjdk.java.net/jfx/pull/417.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/417/head:pull/417

PR: https://git.openjdk.java.net/jfx/pull/417