Disable ICF for Valgrind/ThreadSanitizer Release builds

With ICF the linker merges identical functions into one block of assembly,
which leads to
a) wrong symbols for some functions - which is debugger/Valgrind-unfriendly
b) all ThreadSanitizer annotations end up being one function which makes TSan crazy.

Since we run release code (with -O1 -g) on Valgrind bots,
we have to disable ICF if release_valgrind_build!=0.

BUG=82114
TEST=linux_tsan trybot goes green
Review URL: http://codereview.chromium.org/6991009

git-svn-id: http://src.chromium.org/svn/trunk/src/build@84802 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

common.gypi

@@ -1122,7 +1122,7 @@
               # At gyp time, we test the linker for ICF support; this flag
               # is then provided to us by gyp.  (Currently only gold supports
               # an --icf flag.)
-              ['LINKER_SUPPORTS_ICF==1', {
+              ['LINKER_SUPPORTS_ICF==1 and release_valgrind_build==0', {
                 'ldflags': [
                   '-Wl,--icf=safe',
                 ]