Separate WAsm micro-kernels and scalar micro-kernels

- WAsm-specific microkernels explicitly use f32.min/f32.max WAsm instructions
- About 2% end-to-end improvement on x86, no change on ARM64

PiperOrigin-RevId: 283845483
diff --git a/test/f32-gemminc.yaml b/test/f32-gemminc.yaml
index 308a31e..0b2a9dd 100644
--- a/test/f32-gemminc.yaml
+++ b/test/f32-gemminc.yaml
@@ -201,6 +201,12 @@
   k-block: 4
 - name: xnn_f32_gemminc_ukernel_6x8s4__psimd
   k-block: 4
+- name: xnn_f32_gemminc_ukernel_1x4__wasm
+  k-block: 1
+- name: xnn_f32_gemminc_ukernel_2x4__wasm
+  k-block: 1
+- name: xnn_f32_gemminc_ukernel_4x4__wasm
+  k-block: 1
 - name: xnn_f32_gemminc_ukernel_1x4__scalar
   k-block: 1
 - name: xnn_f32_gemminc_ukernel_2x4__scalar