cranelift: Merge all run tests into runtests dir

With this change we now reuse tests across multiple arches.

Duplicate tests were merged into the same file where possible.
Some legacy x86 tests were left in separate files due to incompatibilities with the rest of the test suite.

cranelift/filetests/filetests/runtests/div-checks.clif

@@ -0,0 +1,35 @@
+test run
+target aarch64
+target arm
+target s390x
+set avoid_div_traps=false
+target x86_64 machinst
+
+function %i8(i8, i8) -> i8 {
+block0(v0: i8, v1: i8):
+  v2 = srem.i8 v0, v1
+  return v2
+}
+; run: %i8(0x80, 0xff) == 0
+; run: %i8(0x2, 0x7) == 0x2
+
+function %i16(i16, i16) -> i16 {
+block0(v0: i16, v1: i16):
+  v2 = srem.i16 v0, v1
+  return v2
+}
+; run: %i16(0x8000, 0xffff) == 0
+
+function %i32(i32, i32) -> i32 {
+block0(v0: i32, v1: i32):
+  v2 = srem.i32 v0, v1
+  return v2
+}
+; run: %i32(0x80000000, 0xffffffff) == 0
+
+function %i64(i64, i64) -> i64 {
+block0(v0: i64, v1: i64):
+  v2 = srem.i64 v0, v1
+  return v2
+}
+; run: %i32(0x800000000000000, 0xffffffffffffffff) == 0