py/compile: Improve the line numbering precision for comprehensions.

The line number for comprehensions is now always reported as the correct
global location in the script, instead of just "line 1".

py/compile.c

@@ -3112,6 +3112,9 @@ STATIC void compile_scope(compiler_t *comp, scope_t *scope, pass_kind_t pass) {
             scope->num_pos_args = 1;
         }
 
+        // Set the source line number for the start of the comprehension
+        EMIT_ARG(set_source_line, pns->source_line);
+
         if (scope->kind == SCOPE_LIST_COMP) {
             EMIT_ARG(build, 0, MP_EMIT_BUILD_LIST);
         } else if (scope->kind == SCOPE_DICT_COMP) {

tests/cmdline/cmd_showbc.py.exp

@@ -449,6 +449,7 @@ arg names: * * *
 (N_STATE 9)
 (N_EXC_STACK 0)
   bc=-\\d\+ line=1
+  bc=0 line=59
 00 LOAD_NULL
 01 LOAD_FAST 2
 02 LOAD_NULL
@@ -471,6 +472,7 @@ arg names: * * *
 (N_STATE 10)
 (N_EXC_STACK 0)
   bc=-\\d\+ line=1
+  bc=0 line=60
 00 BUILD_LIST 0
 02 LOAD_FAST 2
 03 GET_ITER_STACK