[build] Update to using pb 3

Updating the build to the new version of bonnibel. This also includes
some updates to make sure things keep working with LLVM 11.

scripts/parse_syms.py

@@ -1,10 +0,0 @@
-#!/usr/bin/env python3
-
-def parse_elf(filename):
-    import struct
-    with open(filename, 'rb') as elf:
-
-if __name__ == "__main__":
-    import sys
-    for arg in sys.argv[1:]:
-        parse_elf(arg)

scripts/psf_to_cpp.py

@@ -1,27 +0,0 @@
-#!/usr/bin/env python3
-
-from fontpsf import PSF2
-
-def print_header(filename):
-    font = PSF2.load(filename)
-
-    print("#pragma once")
-    print(f"// This file was autogenerated by psf_to_cpp.py from {font.filename}\n")
-
-    print(f"const uint8_t font_glyph_size = {font.charsize};")
-    print(f"const uint8_t font_glyph_width = {font.dimension[0]};")
-    print(f"const uint8_t font_glyph_height = {font.dimension[1]};")
-    print(f"const uint16_t font_glyph_count = {font.count};\n")
-
-    print('const uint8_t font_glyph_data[] = {')
-
-    for glyph in font:
-        print("    ", "".join([f"0x{b:02x}," for b in glyph.data]), end="")
-        print(" // {}".format(glyph.description()))
-
-    print("};")
-
-if __name__ == "__main__":
-    import sys
-    for filename in sys.argv[1:]:
-        print_header(filename)