[llvm] [FastIsel] Get the right register type for call instruction (PR #164565)

[Luo Yuanke via llvm-commits]

================
@@ -1977,8 +1977,13 @@ SDValue SelectionDAGBuilder::getValueImpl(const Value *V) {
   if (const Instruction *Inst = dyn_cast<Instruction>(V)) {
     Register InReg = FuncInfo.InitializeRegForValue(Inst);
 
+    std::optional<CallingConv::ID> CallConv;
+    auto *CI = dyn_cast<CallInst>(Inst);
----------------
LuoYuanke wrote:

I try to create a test case for `callbr`, but I got llc crash with below case. It seems x86 don't support half or bfloat type in inline assembly. 

```
define half @test1(float %x) {
entry:
  %ret = callbr half asm "vxorps $1, $1, $0 jmp ${2:l}", "=x,x,!i"(float %x)
          to label %normal [label %abnormal]
normal:
  ret half %ret

abnormal:
  ret half 1.0
}
```
error: couldn't allocate output register for constraint 'x'

I also got llc crash when running below test case for `invoke`.
```
declare bfloat @pers(...)

declare bfloat @foo();

define bfloat @test_lp() personality ptr @pers {
entry:
  %1 = invoke bfloat @foo()
          to label %then unwind label %hotlp

then:
  ret bfloat %1

hotlp:
  %2 = landingpad { ptr, bfloat }
          cleanup
  br label %lpret

lpret:
  %3 = extractvalue { ptr, bfloat } %2, 1
  ret bfloat %3
}
```
So I'd like to keep it as `CallInst` for now. When bfloat is better supported in `callbr` and `invoke`, we can review `CallInst` and support more call-alike instruction.

https://github.com/llvm/llvm-project/pull/164565