[API request] Raise to integer power.

[gnzlbg]

Raising scalars and vectors to integer powers is very common (e.g. llvm.powi), so I think the following APIs would be very useful:

• double Sleef_ipow_u10(double x, int32_t y);
• __m128d Sleef_ipowd2_u10(__m128d x, int32_t y);
• __m256d Sleef_ipowd4_u10(__m256d x, int32_t y);
• __m512d Sleef_ipowd8_u10(__m512d x, int32_t y);
• float Sleef_ipowf_u10(float x, int32_t y);
• __m128 Sleef_ipowf4_u10(__m128 x, int32_t y);
• __m256 Sleef_ipowf8_u10(__m256 x, int32_t y);
• __m512 Sleef_ipowf16_u10(__m512 x, int32_t y);

[shibatch]

Okay, I will try.