[foreign-abi] [Rev 01] RFR: 8241148: need a way to create MemorySegment with contents from java String and a way to read a C char* as java String

[Athijegannathan Sundararajan]

> Adding utility methods to ForeignUnsafe class.

Athijegannathan Sundararajan has updated the pull request incrementally with one additional commit since the last
revision:

  * renamed makeNativeString as toCString
  * added Charset accepting variant for toCString
  * fixed test to compare PATH value with System.getenv("PATH")

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Changes:
  - all: https://git.openjdk.java.net/panama-foreign/pull/55/files
  - new: https://git.openjdk.java.net/panama-foreign/pull/55/files/b2ec10ae..f7843a08

Webrevs:
 - full: https://webrevs.openjdk.java.net/panama-foreign/55/webrev.01
 - incr: https://webrevs.openjdk.java.net/panama-foreign/55/webrev.00-01

  Stats: 31 lines in 3 files changed: 12 ins; 0 del; 19 mod
  Patch: https://git.openjdk.java.net/panama-foreign/pull/55.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-foreign pull/55/head:pull/55

PR: https://git.openjdk.java.net/panama-foreign/pull/55