Rename intel to x86.

x86 is the more accurate name, as there are non-Intel x86 implementations.

Fixes #263.

cranelift/filetests/isa/x86/abi64.cton

@@ -0,0 +1,32 @@
+; Test the legalization of function signatures.
+test legalizer
+set is_64bit
+isa x86
+
+; regex: V=v\d+
+
+function %f() {
+    sig0 = (i32) -> i32 system_v
+    ; check: sig0 = (i32 [%rdi]) -> i32 [%rax] system_v
+
+    sig1 = (i64) -> b1 system_v
+    ; check: sig1 = (i64 [%rdi]) -> b1 [%rax] system_v
+
+    sig2 = (f32, i64) -> f64 system_v
+    ; check: sig2 = (f32 [%xmm0], i64 [%rdi]) -> f64 [%xmm0] system_v
+
+ebb0:
+    return
+}
+
+function %pass_stack_int64(i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64 vmctx) spiderwasm {
+    sig0 = (i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64 vmctx) spiderwasm
+    fn0 = sig0 u0:0
+
+ebb0(v0: i64, v1: i64, v2: i64, v3: i64, v4: i64, v5: i64, v6: i64, v7: i64, v8: i64, v9: i64, v10: i64, v11: i64, v12: i64, v13: i64, v14: i64, v15: i64, v16: i64, v17: i64, v18: i64, v19: i64, v20: i64):
+    call fn0(v0, v1, v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12, v13, v14, v15, v16, v17, v18, v19, v20)
+    jump ebb1
+
+ebb1:
+    return
+}