This reduces preprocessor-expanded source size by 64,359 from

gen         (   21 files):    71,570 to    1,613,100 (   23x)
src         (  624 files):   367,830 to   52,964,659 (  144x)
test        (  392 files):   490,924 to   37,360,916 (   76x)
third_party (  432 files):   239,085 to    9,547,902 (   40x)
total       ( 1521 files): 1,184,093 to  102,461,098 (   87x)

to

gen         (   21 files):    71,570 to    1,613,100 (   23x)
src         (  624 files):   367,837 to   52,919,005 (  144x)
test        (  392 files):   490,924 to   37,342,211 (   76x)
third_party (  432 files):   239,085 to    9,547,902 (   40x)
total       ( 1521 files): 1,184,100 to  102,396,739 (   86x)

Bug: v8:8562
Change-Id: Iee474e22ababa1e080b8d6359af4d0076903e59a
Reviewed-on: https://chromium-review.googlesource.com/c/1384091Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58424}