Revert of [build] Introduce an embedder version string (patchset #2 id:20001 of https://codereview.chromium.org/2619213002/ )

Reason for revert:
Seems to break the Chromium build: https://codereview.chromium.org/2619193005/

Message:

[1832/9671] CXX obj/v8/v8_base/version.o
FAILED: obj/v8/v8_base/version.o
/b/c/cipd/goma/gomacc ../../third_party/llvm-build/Release+Asserts/bin/clang++ -MMD -MF obj/v8/v8_base/version.o.d -DV8_DEPRECATION_WARNINGS -DDCHECK_ALWAYS_ON=1 -DUSE_UDEV -DUI_COMPOSITOR_IMAGE_TRANSPORT -DUSE_AURA=1 -DUSE_PANGO=1 -DUSE_CAIRO=1 -DUSE_GLIB=1 -DUSE_NSS_CERTS=1 -DUSE_X11=1 -DUSE_PROPRIETARY_CODECS -DFULL_SAFE_BROWSING -DSAFE_BROWSING_CSD -DSAFE_BROWSING_DB_LOCAL -DCHROMIUM_BUILD -DENABLE_MEDIA_ROUTER=1 -DFIELDTRIAL_TESTING_ENABLED -DCR_CLANG_REVISION=289944-2 -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -DNDEBUG -DNVALGRIND -DDYNAMIC_ANNOTATIONS_ENABLED=0 -DV8_I18N_SUPPORT -DENABLE_HANDLE_ZAPPING -DV8_USE_EXTERNAL_STARTUP_DATA -DV8_TARGET_ARCH_X64 -DDEBUG -DU_USING_ICU_NAMESPACE=0 -DU_ENABLE_DYLOAD=0 -DU_STATIC_IMPLEMENTATION -DICU_UTIL_DATA_IMPL=ICU_UTIL_DATA_FILE -I../.. -Igen -I../../v8 -I../../v8/include -I../../third_party/icu/source/common -I../../third_party/icu/source/i18n -fno-strict-aliasing --param=ssp-buffer-size=4 -fstack-protector -funwind-tables -fPIC -pipe -B../../third_party/binutils/Linux_x64/Release/bin -fcolor-diagnostics -fdebug-prefix-map=/b/c/b/linux/src=. -m64 -march=x86-64 -pthread -g1 --sysroot=../../build/linux/debian_wheezy_amd64-sysroot -fvisibility=hidden -Xclang -load -Xclang ../../third_party/llvm-build/Release+Asserts/lib/libFindBadConstructs.so -Xclang -add-plugin -Xclang find-bad-constructs -Xclang -plugin-arg-find-bad-constructs -Xclang check-ipc -Wheader-hygiene -Wstring-conversion -Wtautological-overlap-compare -Werror -Wall -Wno-unused-variable -Wno-missing-field-initializers -Wno-unused-parameter -Wno-c++11-narrowing -Wno-covered-switch-default -Wno-deprecated-register -Wno-unneeded-internal-declaration -Wno-inconsistent-missing-override -Wno-shift-negative-value -Wno-undefined-var-template -Wno-nonportable-include-path -Wno-address-of-packed-member -Wsign-compare -Winconsistent-missing-override -Wshorten-64-to-32 -O3 -fno-ident -fdata-sections -ffunction-sections -fno-threadsafe-statics -fvisibility-inlines-hidden -std=gnu++11 -fno-rtti -fno-exceptions -Wno-deprecated -c ../../v8/src/version.cc -o obj/v8/v8_base/version.o
../../v8/src/version.cc:42:34: error: use of undeclared identifier 'V8_EMBEDDER_STRING'
const char* Version::embedder_ = V8_EMBEDDER_STRING;
                                 ^
1 error generated.

Original issue's description:
> [build] Introduce an embedder version string
>
> Sometimes, the embedder might want to merge a fix to an abandoned branch
> or to a supported branch but the fix is not relevant to Chromium.
> This adds a new version string that the embedder can set on compile time
> and that will be appended to the official V8 version.
> The separator must be provided in the string. For instance, to have a
> full version string like "5.5.372.37.custom.1", the embedder must set
> V8_EMBEDDER_STRING to ".custom.1".
>
> Related Node.js issue: https://github.com/nodejs/node/pull/9754
>
> BUG=v8:5740
> R=machenbach@chromium.org,hablich@chromium.com,ofrobots@google.com
>
> Review-Url: https://codereview.chromium.org/2619213002
> Cr-Commit-Position: refs/heads/master@{#42175}
> Committed: https://chromium.googlesource.com/v8/v8/+/fc86d4329b253bf21c1dd85469f1ef4b6e5ba01a

TBR=hablich@chromium.com,machenbach@chromium.org,ofrobots@google.com,mic.besace@gmail.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:5740

Review-Url: https://codereview.chromium.org/2621033002
Cr-Commit-Position: refs/heads/master@{#42182}