[llvm] [X86][GlobalISel] Support G_FCMP for scalar cases (PR #123598)

[Evgenii Kudriashov via llvm-commits]

================
@@ -450,7 +450,8 @@ X86LegalizerInfo::X86LegalizerInfo(const X86Subtarget &STI,
   getActionDefinitionsBuilder(G_FCMP)
       .legalIf([=](const LegalityQuery &Query) {
         return (HasSSE1 && typePairInSet(0, 1, {{s8, s32}})(Query)) ||
-               (HasSSE2 && typePairInSet(0, 1, {{s8, s64}})(Query));
+               (HasSSE2 && typePairInSet(0, 1, {{s8, s64}})(Query)) ||
----------------
e-kud wrote:

It should be `HasSSE1 || UseX87` and `HasSSE2 || X87` if we want to reach selection of `UCOM_FpIr32` and `UCOM_FpIr64`.

https://github.com/llvm/llvm-project/pull/123598