debuginfo: store location of loop boundary (#41857)

Since lowering always inserts gotos and other instructions after loop
bodies, this allows debuggers to give a more useful location for these
instructions.

fixes JuliaDebug/JuliaInterpreter.jl#485

Author: simeonschaub

src/julia-parser.scm

@@ -1376,14 +1376,14 @@
             (if (eq? word 'quote)
                 (list 'quote blk)
                 blk))))
-       ((while)  (begin0 (list 'while (parse-cond s) (parse-block s))
+       ((while)  (begin0 (list 'while (parse-cond s) (append (parse-block s) (list (line-number-node s))))
                          (expect-end s word)))
        ((for)
         (let* ((ranges (parse-comma-separated-iters s))
                (body   (parse-block s)))
           (expect-end s word)
           `(for ,(if (length= ranges 1) (car ranges) (cons 'block ranges))
-                ,body)))
+                ,(append body (list (line-number-node s))))))
 
        ((let)
         (let ((binds (if (memv (peek-token s) '(#\newline #\;))

stdlib/Distributed/src/macros.jl

@@ -347,6 +347,9 @@ macro distributed(args...)
     var = loop.args[1].args[1]
     r = loop.args[1].args[2]
     body = loop.args[2]
+    if Meta.isexpr(body, :block) && body.args[end] isa LineNumberNode
+        resize!(body.args, length(body.args) - 1)
+    end
     if na==1
         syncvar = esc(Base.sync_varname)
         return quote

test/testhelpers/coverage_file.info

@@ -4,7 +4,8 @@ DA:4,1
 DA:5,0
 DA:7,1
 DA:8,1
-DA:9,5
+DA:9,3
+DA:10,5
 DA:11,1
 DA:12,1
 DA:14,0

test/testhelpers/coverage_file.info.bad

@@ -4,7 +4,8 @@ DA:4,1
 DA:5,0
 DA:7,1
 DA:8,1
-DA:9,5
+DA:9,3
+DA:10,5
 DA:11,1
 DA:12,1
 DA:14,0
@@ -14,6 +15,6 @@ DA:19,1
 DA:20,1
 DA:22,1
 DA:1234,0
-LH:11
-LF:15
+LH:12
+LF:16
 end_of_record