[Backport to 14] Limit the instructions that enable BFloat16ArithmeticINTEL capability (#3586)

We should not require `CapabilityBFloat16ArithmeticINTEL` for the
instructions that are allowed by `SPV_KHR_bfloat16` (e.g. conversion
instructions). Without the fix the test is failing with:

```
RequiresExtension: Feature requires the following SPIR-V extension:
 SPV_INTEL_bfloat16_arithmetic
```

Author: vmaksimo

lib/SPIRV/libSPIRV/SPIRVModule.cpp

@@ -1578,7 +1578,8 @@ SPIRVInstruction *SPIRVModuleImpl::addUnaryInst(Op TheOpCode,
                                                 SPIRVType *TheType,
                                                 SPIRVValue *Op,
                                                 SPIRVBasicBlock *BB) {
-  if (TheType->isTypeFloat(16, FPEncodingBFloat16KHR) && TheOpCode != OpDot)
+  if (TheType->isTypeFloat(16, FPEncodingBFloat16KHR) &&
+      (TheOpCode == OpFNegate || isUnaryPredicateOpCode(TheOpCode)))
     addCapability(internal::CapabilityBFloat16ArithmeticINTEL);
   return addInstruction(
       SPIRVInstTemplateBase::create(TheOpCode, TheType, getId(),

test/extensions/KHR/SPV_KHR_bfloat16/conversions.ll

@@ -0,0 +1,56 @@
+; RUN: llvm-as %s -o %t.bc
+; RUN: llvm-spirv %t.bc --spirv-ext=+SPV_KHR_bfloat16 -o %t.spv
+; RUN: llvm-spirv %t.spv -to-text -o - | FileCheck %s --check-prefix=CHECK-SPIRV
+
+; RUN: llvm-spirv -r %t.spv -o %t.rev.bc
+; RUN: llvm-dis %t.rev.bc -o - | FileCheck %s --check-prefix=CHECK-LLVM
+
+; RUN: not llvm-spirv %t.bc 2>&1 >/dev/null | FileCheck %s --check-prefix=CHECK-ERROR
+; RUN: not llvm-spirv %t.bc --spirv-ext=+SPV_INTEL_bfloat16_arithmetic 2>&1 >/dev/null | FileCheck %s --check-prefix=CHECK-ERROR
+; CHECK-ERROR: RequiresExtension: Feature requires the following SPIR-V extension:
+
+target datalayout = "e-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024-n8:16:32:64"
+target triple = "spir64-unknown-unknown"
+
+; CHECK-SPIRV: Capability BFloat16TypeKHR
+; CHECK-SPIRV-NOT: Capability BFloat16ArithmeticINTEL
+; CHECK-SPIRV-NOT: Extension "SPV_INTEL_bfloat16_arithmetic"
+; CHECK-SPIRV: Extension "SPV_KHR_bfloat16"
+; CHECK-SPIRV: TypeFloat [[BFLOAT:[0-9]+]] 16 0
+; CHECK-SPIRV: Variable [[#]] [[ADDR1:[0-9]+]]
+; CHECK-SPIRV: Load [[BFLOAT]] [[DATA1:[0-9]+]] [[ADDR1]]
+; CHECK-SPIRV: ConvertFToU [[#]] [[#]] [[DATA1]]
+; CHECK-SPIRV: ConvertFToS [[#]] [[#]] [[DATA1]]
+; CHECK-SPIRV: ConvertSToF [[BFLOAT]] [[#]] [[#]]
+; CHECK-SPIRV: ConvertUToF [[BFLOAT]] [[#]] [[#]]
+
+
+; CHECK-LLVM: [[ADDR1:[%a-z0-9]+]] = alloca bfloat
+; CHECK-LLVM: [[DATA1:[%a-z0-9]+]] = load bfloat, bfloat* [[ADDR1]]
+; CHECK-LLVM: %OpConvertFToU = fptoui bfloat [[DATA1]] to i32
+; CHECK-LLVM: %OpConvertFToS = fptosi bfloat [[DATA1]] to i32
+; CHECK-LLVM: %OpConvertSToF = sitofp i32 0 to bfloat
+; CHECK-LLVM: %OpConvertUToF = uitofp i32 0 to bfloat
+
+define spir_kernel void @testConversions() {
+entry:
+  %addr1 = alloca bfloat
+  %data1 = load bfloat, bfloat* %addr1
+  %OpConvertFToU = fptoui bfloat %data1 to i32
+  %OpConvertFToS = fptosi bfloat %data1 to i32
+  %OpConvertSToF = sitofp i32 0 to bfloat
+  %OpConvertUToF = uitofp i32 0 to bfloat
+  ret void
+}
+
+!opencl.enable.FP_CONTRACT = !{}
+!opencl.spir.version = !{!0}
+!opencl.ocl.version = !{!1}
+!opencl.used.extensions = !{!2}
+!opencl.used.optional.core.features = !{!3}
+!opencl.compiler.options = !{!3}
+
+!0 = !{i32 1, i32 2}
+!1 = !{i32 2, i32 0}
+!2 = !{!"cl_khr_fp16"}
+!3 = !{}