runners: jlink: win32: search for valid JLink.exe

[JordanYates]

Since "JLink.exe" is also an executable distributed with JDK's, do an explicit search on the standard SEGGER install directories for a JTAG "JLink.exe" before falling back to whatever is first on PATH.

Fixes #51825.

[theadib]

Hello Jordan,
you only test for "versioned" JLink folders: ... SEGGER" / "JLink_V*"))
Please could you also add to the tests the "unversioned" variant: .../SEGGER/JLink <- without "_V*"

That is created when selecting "update existing installation" instead "create new instance" during installation proccess.

Thanks, Adib.

[theadib]

... and maybe add the USERs Program folder in the case the user has selected "for this user only"
/SEGGER/JLink
where is Pythons: pathlib.Path.home()

[JordanYates]

Added Path.home() to roots checked, and JLink as a preferred folder to use:

[rruuaanng]

If the JLINK_HOME environment variable is set, we should start the search directly from there. This is how my local branch is currently configured. WDYT? @JordanYates

[JordanYates]

If the JLINK_HOME environment variable is set, we should start the search directly from there. This is how my local branch is currently configured. WDYT? @JordanYates

Is that an environment variable set by the JLink install tools?

[rruuaanng]

If the environment variable is set, we should start the search directly from there. This is how my local branch is currently configured. WDYT? @JordanYatesJLINK_HOME

Is that an environment variable set by the JLink install tools?

No, perhaps this is a habit shared by some users, like myself, or others who have the same habit. Maybe I should ask the author for their thoughts on this.

[JordanYates]

If the environment variable is set, we should start the search directly from there. This is how my local branch is currently configured. WDYT? @JordanYatesJLINK_HOME

Is that an environment variable set by the JLink install tools?

No, perhaps this is a habit shared by some users, like myself, or others who have the same habit. Maybe I should ask the author for their thoughts on this.

IMO if people are not installing it in one of the 3 standard locations, it is not unreasonable to require them to either setup $PATH manually or explicitly specify --commander on the command line.

[rruuaanng]

That's what I want to say, I don't like to install software on C: disk.