Remove latexmath invocations where suitable due to interference with norm rule extraction and general searching in HTML/PDF ISA manuals

[james-ball-qualcomm]

See riscv/docs-resources#126 for a thorough discussion of the problem and the proposed solution.

[james-ball-qualcomm]

There are currently 389 instances of latexmath in the ISA manuals.

[james-ball-qualcomm]

I'm trying GitHub copilot to make the changes. I just told it "Replace calls to latexmath in AsciiDoc source file with regular characters wherever suitable." and it is chugging away.

[james-ball-qualcomm]

@wmat, @aswaterman, @davidharrishmc, @jordancarlin

[james-ball-qualcomm]

Then I told it to "Replace <= with {le} and => with {ge}" and then "Replace right arrow with -> and left arrow with <-". That got it down to 303 instances of latexmath. I'll commit that and then keep going.

[james-ball-qualcomm]

Now I asked it to "What about remaining uses of latexmath?" and it found more it could safely replace and then showed me examples of those it doesn't think it should replace which I agreed with. Down to 241 remaining calls to latexmath.

Complex mathematical expressions (should keep):
Division equation: latexmath:[$\textrm{dividend} = \textrm{divisor} \times \textrm{quotient} + \textrm{remainder}$] in [m-st-ext.adoc](vscode-file://vscode-app/c:/Users/jameball/AppData/Local/Programs/Microsoft%20VS%20Code/resources/app/out/vs/code/electron-browser/workbench/workbench.html)
Log expressions: latexmath:[$\log_2n$] in [machine.adoc](vscode-file://vscode-app/c:/Users/jameball/AppData/Local/Programs/Microsoft%20VS%20Code/resources/app/out/vs/code/electron-browser/workbench/workbench.html)
Typewriter font: latexmath:[${\tt pmpcfg}_i$] and latexmath:[${\tt pmpaddr}_i$] in PMP sections
Formal model notation: latexmath:[$\circ$], latexmath:[$\bullet$], arrows in [mm-formal.adoc](vscode-file://vscode-app/c:/Users/jameball/AppData/Local/Programs/Microsoft%20VS%20Code/resources/app/out/vs/code/electron-browser/workbench/workbench.html)
Variable placeholders: latexmath:[$i$], latexmath:[$w$], latexmath:[$r$], latexmath:[$n$] in prose

[james-ball-qualcomm]

BTW, I see a bunch of uses of "≠" which is the Unicode character ≠. Going to add this macro to our adoc header like the le, ge, etc. macros since those are much more readable. Found in rv32.adoc.

Never mind, a macro for ne is already present. Going to use it and ensure adoc handles it properly.

Actually, I'll create a separate issue for that and not bother changing here. Create #2406 but can't assign it to anymore (permissions issue for me?).

[james-ball-qualcomm]

I see many remaining calls to latexmath are just using it for exponents (e.g., 2^32). I see now that AsciiDoc lets you say 2^32^ to get superscript so I'll try all this over again giving Copilot this additional information since it has already converted latexmath with exponents already. Here's what I'll tell it "Change latexmath calls using exponents to use the AsciiDoc superscript syntax"

[james-ball-qualcomm]

Started from scratch again since the latexmath calls using exponents have already been converted to normal characters (e.g., 2^32) so thought Copilot might do better with the following "Replace calls to latexmath in AsciiDoc source file with regular characters wherever suitable. Also, replace <= with {le} and => with {ge}, replace right arrow with -> and left arrow with <-, and change latexmath calls using exponents to use the AsciiDoc superscript syntax"

[james-ball-qualcomm]

Copilot didn't like me combining all these requests so splitting them up into individual requests like I did originally.

[james-ball-qualcomm]

Just learned that Copilot has an "Agent" mode that I should be using instead of "Edit" since edit is just specific files but Agent will make changes to all files.

So, first asked Copilot "Replace calls to latexmath in all AsciiDoc source files *.adoc with regular characters wherever suitable.". Noticed it changed many exponents like latexmath:[$2^32$] to just 2^32 but adoc needs 2^32^ for superscript. So, told copilot "You aren't using the correct AsciiDoc syntax for superscript. You have to place an additional ^ after the end of the superscript text."

Noticed it put in the Unicode infinity character instead of using the word "infinity" so told it "Use {inf} instead of the infinity Unicode character".

[james-ball-qualcomm]

Told it "Use {le} instead of the Unicode less-than-or-equal-to character and {ge} instead of the Unicode greater-than-or-equal-to character."

Added following macros to priv/unpriv for Unicode char corresponding to latexmath of the same name:

:circ: ○
:bullet: ∙
:times: ×

Replace some explicit uses of Unicode 8800 (not-equal) to use {ne} instead.