Fix broken namespace renaming in SIMD (#453)

src/simd/approx.hpp

@@ -13,6 +13,7 @@
 // detail concerning the approximations.
 
 namespace arb {
+namespace simd {
 namespace simd_detail {
 
 // Exponential:
@@ -81,4 +82,5 @@ constexpr double Q3log = 4.52279145837532221105e1;
 constexpr double Q4log = 1.12873587189167450590e1;
 
 } // namespace simd_detail
+} // namespace simd
 } // namespace arb

src/simd/avx.hpp

@@ -12,7 +12,7 @@
 #include <simd/implbase.hpp>
 
 namespace arb {
-namespace simsimd {
+namespace simd {
 namespace simd_detail {
 
 struct avx_int4;

src/simd/native.hpp

@@ -33,11 +33,13 @@ struct native {
 
 #define ARB_DEF_NATIVE_SIMD_(T, N, A)\
 namespace arb {\
+namespace simd {\
 namespace simd_abi {\
 template <> struct native<T, N> {\
     using type = typename A<T, N>::type;\
 };\
 }\
+}\
 }