Revert "Rollup merge of #133418 - Zalathar:spans, r=jieyouxu"

This reverts commit adf9b5fcd1, reversing
changes made to af1ca153d4.

Reverting due to <https://github.com/rust-lang/rust/issues/133606>.

compiler/rustc_codegen_llvm/src/coverageinfo/ffi.rs

@@ -1,4 +1,6 @@
-use rustc_middle::mir::coverage::{CounterId, CovTerm, ExpressionId};
+use rustc_middle::mir::coverage::{CounterId, CovTerm, ExpressionId, SourceRegion};
+
+use crate::coverageinfo::mapgen::LocalFileId;
 
 /// Must match the layout of `LLVMRustCounterKind`.
 #[derive(Copy, Clone, Debug)]
@@ -124,23 +126,37 @@ pub(crate) struct CoverageSpan {
     /// Local index into the function's local-to-global file ID table.
     /// The value at that index is itself an index into the coverage filename
     /// table in the CGU's `__llvm_covmap` section.
-    pub(crate) file_id: u32,
+    file_id: u32,
 
     /// 1-based starting line of the source code span.
-    pub(crate) start_line: u32,
+    start_line: u32,
     /// 1-based starting column of the source code span.
-    pub(crate) start_col: u32,
+    start_col: u32,
     /// 1-based ending line of the source code span.
-    pub(crate) end_line: u32,
+    end_line: u32,
     /// 1-based ending column of the source code span. High bit must be unset.
-    pub(crate) end_col: u32,
+    end_col: u32,
+}
+
+impl CoverageSpan {
+    pub(crate) fn from_source_region(
+        local_file_id: LocalFileId,
+        code_region: &SourceRegion,
+    ) -> Self {
+        let file_id = local_file_id.as_u32();
+        let &SourceRegion { start_line, start_col, end_line, end_col } = code_region;
+        // Internally, LLVM uses the high bit of `end_col` to distinguish between
+        // code regions and gap regions, so it can't be used by the column number.
+        assert!(end_col & (1u32 << 31) == 0, "high bit of `end_col` must be unset: {end_col:#X}");
+        Self { file_id, start_line, start_col, end_line, end_col }
+    }
 }
 
 /// Must match the layout of `LLVMRustCoverageCodeRegion`.
 #[derive(Clone, Debug)]
 #[repr(C)]
 pub(crate) struct CodeRegion {
-    pub(crate) cov_span: CoverageSpan,
+    pub(crate) span: CoverageSpan,
     pub(crate) counter: Counter,
 }
 
@@ -148,7 +164,7 @@ pub(crate) struct CodeRegion {
 #[derive(Clone, Debug)]
 #[repr(C)]
 pub(crate) struct BranchRegion {
-    pub(crate) cov_span: CoverageSpan,
+    pub(crate) span: CoverageSpan,
     pub(crate) true_counter: Counter,
     pub(crate) false_counter: Counter,
 }
@@ -157,7 +173,7 @@ pub(crate) struct BranchRegion {
 #[derive(Clone, Debug)]
 #[repr(C)]
 pub(crate) struct MCDCBranchRegion {
-    pub(crate) cov_span: CoverageSpan,
+    pub(crate) span: CoverageSpan,
     pub(crate) true_counter: Counter,
     pub(crate) false_counter: Counter,
     pub(crate) mcdc_branch_params: mcdc::BranchParameters,
@@ -167,6 +183,6 @@ pub(crate) struct MCDCBranchRegion {
 #[derive(Clone, Debug)]
 #[repr(C)]
 pub(crate) struct MCDCDecisionRegion {
-    pub(crate) cov_span: CoverageSpan,
+    pub(crate) span: CoverageSpan,
     pub(crate) mcdc_decision_params: mcdc::DecisionParameters,
 }