Use shared utils in wasm-sourcemap.py. NFC (#25875)

I suppose at some point the idea was to allow this script to be shipped
and uses outside of emscripten, but I think that ship has sailed.

Author: sbc100

tools/wasm-sourcemap.py

@@ -17,14 +17,12 @@
 import re
 import sys
 from math import floor, log
-from pathlib import Path
-from subprocess import PIPE, Popen
 
 __scriptdir__ = os.path.dirname(os.path.abspath(__file__))
 __rootdir__ = os.path.dirname(__scriptdir__)
 sys.path.insert(0, __rootdir__)
 
-from tools import utils
+from tools import shared, utils
 from tools.system_libs import DETERMINISTIC_PREFIX
 
 EMSCRIPTEN_PREFIX = utils.normalize_path(utils.path_from_root())
@@ -233,24 +231,18 @@ def extract_comp_dir_map(text):
 
 def read_dwarf_entries(wasm, options):
   if options.dwarfdump_output:
-    output = Path(options.dwarfdump_output).read_bytes()
+    output = utils.read_file(options.dwarfdump_output)
   elif options.dwarfdump:
     logger.debug('Reading DWARF information from %s' % wasm)
     if not os.path.exists(options.dwarfdump):
-      logger.error('llvm-dwarfdump not found: ' + options.dwarfdump)
-      sys.exit(1)
-    process = Popen([options.dwarfdump, '-debug-info', '-debug-line', '--recurse-depth=0', wasm], stdout=PIPE)
-    output, err = process.communicate()
-    exit_code = process.wait()
-    if exit_code != 0:
-      logger.error('Error during llvm-dwarfdump execution (%s)' % exit_code)
-      sys.exit(1)
+      utils.exit_with_error('llvm-dwarfdump not found: ' + options.dwarfdump)
+    proc = shared.check_call([options.dwarfdump, '-debug-info', '-debug-line', '--recurse-depth=0', wasm], stdout=shared.PIPE)
+    output = proc.stdout
   else:
-    logger.error('Please specify either --dwarfdump or --dwarfdump-output')
-    sys.exit(1)
+    utils.exit_with_error('Please specify either --dwarfdump or --dwarfdump-output')
 
   entries = []
-  debug_line_chunks = re.split(r"debug_line\[(0x[0-9a-f]*)\]", output.decode('utf-8'))
+  debug_line_chunks = re.split(r"debug_line\[(0x[0-9a-f]*)\]", output)
   map_stmt_list_to_comp_dir = extract_comp_dir_map(debug_line_chunks[0])
   for stmt_list, line_chunk in zip(debug_line_chunks[1::2], debug_line_chunks[2::2]):
     comp_dir = map_stmt_list_to_comp_dir.get(stmt_list, '')