[llvm] [LangRef] Document accessing memory outside of object is UB. (PR #128429)

[Matt Arsenault via llvm-commits]

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@@ -11108,12 +11110,9 @@ operation (that is, the alignment of the memory address). It is the
 responsibility of the code emitter to ensure that the alignment information is
 correct. Overestimating the alignment results in undefined behavior.
 Underestimating the alignment may produce less efficient code. An alignment of
-1 is always safe. The maximum possible alignment is ``1 << 32``. An alignment
-value higher than the size of the loaded type implies memory up to the
-alignment value bytes can be safely loaded without trapping in the default
-address space. Access of the high bytes can interfere with debugging tools, so
-should not be accessed if the function has the ``sanitize_thread`` or
-``sanitize_address`` attributes.
+1 is always safe. The maximum possible alignment is ``1 << 32``. Access of the
+high bytes can interfere with debugging tools, so should not be accessed if the
+function has the ``sanitize_thread`` or ``sanitize_address`` attributes.
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arsenm wrote:

I believe @chandlerc requested the bit about the sanitizers 

https://github.com/llvm/llvm-project/pull/128429