Segmentation fault detected when running ddrgen

[ChengJin01]

Segmentation fault occurred in ddrgen when compiling the latest version of OpenJDK11/OpenJ9/OMR with VS2017.

../ddrgen --blob ../j9ddr.dat --superset ../superset.dat --blacklist blacklist --macrolist ../mac    roList --overrides overrides --show-empty  \
        ../j9ddr_misc29.pdb ../j9gc29.pdb ../j9jvmti29.pdb ../j9prt29.pdb ../j9shr29.pdb ../j9thr    29.pdb ../j9trc29.pdb ../j9vm29.pdb ../jclse11_29.pdb
make[5]: *** [run_omrddrgen.mk:73: ../j9ddr.dat] Segmentation fault
make[5]: Leaving directory '/cygdrive/c/temp1/openj9-openjdk-jdk11/build/windows-x86_64-normal-se    rver-release/vm/ddr'

It worked good last month after fixing all issues with OpenJDK11 on Windows.

I am not too sure whether the problem was caused by recent changes merged in omr/ddr

@keithc-ca, @DanHeidinga

[keithc-ca]

I was able to reproduce this. It fails because it can't resolve typedefs like omr_error_t immediately.
The PostponedType mechanism handles delayed resolution of field types, but PdbScanner::createTypedef also want to copy the type size into the typedef. Perhaps another (later) pass can update sizes of typedefs.

[keithc-ca]

@ChengJin01 This should be fixed by #2944: please close if you agree.