[clang] [Headers][X86] Add rounding and exception notes to conversions (PR #83447)

[Phoebe Wang via cfe-commits]

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@@ -2180,7 +2180,8 @@ _mm256_cvtepi32_pd(__m128i __a)
   return (__m256d)__builtin_convertvector((__v4si)__a, __v4df);
 }
 
-/// Converts a vector of [8 x i32] into a vector of [8 x float].
+/// Converts a vector of [8 x i32] into a vector of [8 x float]. Rounds inexact
+///    results according to the rounding control bits in the MXCSR register.
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phoebewang wrote:

I think we don't need to mention it. This is the default behavior if not mentioned otherwise.

https://github.com/llvm/llvm-project/pull/83447