Supersize: Store whether source path was generated in flags

tools/binary_size/libsupersize/testdata/Console.golden

 # Show pydoc for main types:
 import models
 help(models)
 
 # Show all attributes of all symbols & per-section totals:
 Print(size_info, verbose=True)
 
 # Show two levels of .text, grouped by first two subdirectories
 text_syms = size_info.symbols.WhereInSection("t")
 by_path = text_syms.GroupBySourcePath(depth=2)
 Print(by_path.WhereBiggerThan(1024))
 
 # Show all non-vtable generated symbols
-generated_syms = size_info.symbols.WhereIsGenerated()
-Print(generated_syms.WhereNameMatches(r"vtable").Inverted())
+generated_syms = size_info.symbols.WhereGeneratedByToolchain()
+Print(generated_syms.WhereNameMatches(r"vtable").Inverted().Sorted())
 
 # Show all symbols that have "print" in their name or path, except
 # those within components/.
 # Note: Could have also used Inverted(), as above.
 # Note: Use "help(ExpandRegex)" for more about what {{_print_}} does.
 print_syms = size_info.symbols.WhereMatches(r"{{_print_}}")
 Print(print_syms - print_syms.WherePathMatches(r"^components/"))
 
 # Diff two .size files and save result to a file:
 Print(Diff(size_info1, size_info2), to_file="output.txt")
@@ skipping 108 matching lines @@
 43785380 b@0x0        131072  third_party/fft_fixed.cc
              ff_cos_131072_fixed
 43785380 b@0x0        131072  third_party/fft_float.cc
              ff_cos_65536
 43785380 b@0x2dffe80  200     third_party/icu/ucnv_ext.c
              SaveHistogram::atomic_histogram_pointer
 43785380 b@0x2dffda0  28      third_party/icu/ucnv_ext.c
              g_chrome_content_browser_client
 43785380 b@0x2dffe84  4       third_party/icu/ucnv_ext.c
              g_AnimationFrameTimeHistogram_clazz