[Wasm] Optimize when using br_table only if all conditions read and compare the same variable

#KT-60212 Fixed

compiler/testData/codegen/box/when/kt60212.kt

@@ -0,0 +1,32 @@
+fun box(): String {
+    testIfs()
+    testWhen()
+
+    return "OK"
+}
+
+// From KT-60212
+fun testIfs() {
+    val b1 = 0b11011111
+    if (b1 and 0b10000000 == 0) {
+        fail("A")
+    } else if (b1 and 0b11100000 == 0b11000000) {
+        return
+    } else {
+        fail("C")
+    }
+}
+
+// Snippet from kotlinx-io
+fun testWhen() {
+    val v = test(0xdf)
+    if (v != 1) fail("D")
+}
+
+fun test(b0: Int) = when {
+    b0 and 0x80 == 0 -> 0
+    b0 and 0xe0 == 0xc0 -> 1
+    b0 and 0xf0 == 0xe0 -> 2
+    b0 and 0xf8 == 0xf0 -> 3
+    else -> -1
+}