mcdc-coverage: Update ffi RegionKind to match LLVM's

Author: RenjiSann

compiler/rustc_codegen_llvm/src/coverageinfo/ffi.rs

@@ -99,6 +99,15 @@ pub enum RegionKind {
     /// associated with two counters, each representing the number of times the
     /// expression evaluates to true or false.
     BranchRegion = 4,
+
+    /// A DecisionRegion represents a top-level boolean expression and is
+    /// associated with a variable length bitmap index and condition number.
+    #[allow(dead_code)]
+    MCDCDecisionRegion = 5,
+
+    /// A Branch Region can be extended to include IDs to facilitate MC/DC.
+    #[allow(dead_code)]
+    MCDCBranchRegion = 6,
 }
 
 /// This struct provides LLVM's representation of a "CoverageMappingRegion", encoded into the

compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp

@@ -43,6 +43,8 @@ enum class LLVMRustCounterMappingRegionKind {
   SkippedRegion = 2,
   GapRegion = 3,
   BranchRegion = 4,
+  MCDCDecisionRegion = 5,
+  MCDCBranchRegion = 6,
 };
 
 static coverage::CounterMappingRegion::RegionKind
@@ -58,6 +60,10 @@ fromRust(LLVMRustCounterMappingRegionKind Kind) {
     return coverage::CounterMappingRegion::GapRegion;
   case LLVMRustCounterMappingRegionKind::BranchRegion:
     return coverage::CounterMappingRegion::BranchRegion;
+  case LLVMRustCounterMappingRegionKind::MCDCDecisionRegion:
+    return coverage::CounterMappingRegion::MCDCDecisionRegion;
+  case LLVMRustCounterMappingRegionKind::MCDCBranchRegion:
+    return coverage::CounterMappingRegion::MCDCBranchRegion;
   }
   report_fatal_error("Bad LLVMRustCounterMappingRegionKind!");
 }