Fix typos in exp-based microkernels and evaluation stubs

PiperOrigin-RevId: 343452021
diff --git a/src/math/exp-sse2-lut64-p2.c b/src/math/exp-sse2-lut64-p2.c
index e7cb58d..437629e 100644
--- a/src/math/exp-sse2-lut64-p2.c
+++ b/src/math/exp-sse2-lut64-p2.c
@@ -95,7 +95,7 @@
     __m128 vt = _mm_add_ps(_mm_mul_ps(vn, vminus_ln2_o64_hi), vx);
     vt = _mm_add_ps(_mm_mul_ps(vn, vminus_ln2_o64_lo), vt);
 
-    // Compute degree-2 polynomial approxiatmion for exp(t) on [-log(2)/128, log(2)/128].
+    // Compute degree-2 polynomial approximation for exp(t) on [-log(2)/128, log(2)/128].
     __m128 vp = _mm_mul_ps(vt, vc2);
     vp = _mm_add_ps(vt, _mm_mul_ps(vt, vp));