[gcc r16-3523] docs: Add NoOffload option flag to the internals manual

[Andrew Stubbs]

https://gcc.gnu.org/g:6e0590ba45e8df543133028b0ccf692a21cf2a4d

commit r16-3523-g6e0590ba45e8df543133028b0ccf692a21cf2a4d
Author: Andrew Stubbs <ams@baylibre.com>
Date:   Thu Jul 31 11:05:37 2025 +0000

    docs: Add NoOffload option flag to the internals manual
    
    The NoOffload flag was introduced recently (commit "Don't pass vector params
    through to offload targets").
    
    gcc/ChangeLog:
    
            * doc/options.texi: Document NoOffload.

Diff:
---
 gcc/doc/options.texi | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/gcc/doc/options.texi b/gcc/doc/options.texi
index b46b9977da81..25cd2bcb7977 100644
--- a/gcc/doc/options.texi
+++ b/gcc/doc/options.texi
@@ -529,6 +529,12 @@ code generation.
 @item Param
 This is an option that is a parameter.
 
+@item NoOffload
+This option will not be passed through from the host compiler to any offload
+target compilers via the LTO mechanism.  It is intended for use with
+optimization tuning parameters where settings appropriate for the host system
+are likely to harm the performance of the offload device.
+
 @item Undocumented
 The option is deliberately missing documentation and should not
 be included in the @option{--help} output.