fail at field type mismatch in json2pb #1125

Job	Run time
clang-compile-with-bazel	14m 34s
clang-compile-with-boringssl	20m 33s
clang-compile-with-cmake	2m 37s
clang-compile-with-make	2m 37s
clang-compile-with-make-all-options	4m 21s
gcc-compile-with-bazel	16m 22s
gcc-compile-with-bazel-all-options	19m 11s
gcc-compile-with-boringssl	20m 0s
gcc-compile-with-cmake	2m 56s
gcc-compile-with-cmake-all-options	4m 43s
gcc-compile-with-make	3m 13s
clang-compile-with-bazel-all-options	17m 55s
clang-compile-with-cmake-all-options	4m 32s
clang-unittest	14m 54s
gcc-compile-with-make-all-options	6m 13s
	2h 34m 41s

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