tsan: fix string comparison in Go build script

[dvyukov]

Summary

Some bots failed with:

buildgo.sh: 173: [: linux: unexpected operator
Unknown platform

https://lab.llvm.org/buildbot/#/builders/247/builds/4603

[dyung]

lgtm, and thanks for fixing it.

compiler-rt/lib/tsan/go/buildgo.sh

SRCS="
   ../../sanitizer_common/sanitizer_stack_store.cpp
   ../../sanitizer_common/sanitizer_stackdepot.cpp
   ../../sanitizer_common/sanitizer_stacktrace.cpp
   ../../sanitizer_common/sanitizer_symbolizer.cpp
   ../../sanitizer_common/sanitizer_symbolizer_report.cpp
   ../../sanitizer_common/sanitizer_termination.cpp
 "
 
-if [ "$GOOS" == "linux" ]; then
+if [ "$GOOS" = "linux" ]; then
   OSCFLAGS="-fPIC -Wno-maybe-uninitialized"
   OSLDFLAGS="-lpthread -fPIC -fpie"
   SRCS="
     $SRCS
     ../rtl/tsan_platform_linux.cpp
     ../../sanitizer_common/sanitizer_posix.cpp
     ../../sanitizer_common/sanitizer_posix_libcdep.cpp
     ../../sanitizer_common/sanitizer_procmaps_common.cpp
     ../../sanitizer_common/sanitizer_procmaps_linux.cpp
     ../../sanitizer_common/sanitizer_linux.cpp
     ../../sanitizer_common/sanitizer_linux_libcdep.cpp
     ../../sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cpp
     ../../sanitizer_common/sanitizer_stoptheworld_netbsd_libcdep.cpp
     "
-  if [ "$GOARCH" == "ppc64le" ]; then
+  if [ "$GOARCH" = "ppc64le" ]; then
     ARCHCFLAGS="-m64 -mcpu=power8 -fno-function-sections"
-  elif [ "$GOARCH" == "amd64" ]; then
+  elif [ "$GOARCH" = "amd64" ]; then
     if [ "$GOAMD64" = "v3" ]; then
       ARCHCFLAGS="-m64 -msse4.2"
     else
       ARCHCFLAGS="-m64 -msse3"
     fi
     OSCFLAGS="$OSCFLAGS -ffreestanding -Wno-unused-const-variable -Wno-unknown-warning-option"
-  elif [ "$GOARCH" == "arm64" ]; then
+  elif [ "$GOARCH" = "arm64" ]; then
     ARCHCFLAGS=""
-  elif [ "$GOARCH" == "mips64le" ]; then
+  elif [ "$GOARCH" = "mips64le" ]; then
     ARCHCFLAGS="-mips64 -EL"
-  elif [ "$GOARCH" == "mips64" ]; then
+  elif [ "$GOARCH" = "mips64" ]; then
     ARCHCFLAGS="-mips64 -EB"
-  elif [ "$GOARCH" == "s390x" ]; then
+  elif [ "$GOARCH" = "s390x" ]; then
     SRCS="$SRCS ../../sanitizer_common/sanitizer_linux_s390.cpp"
     ARCHCFLAGS=""
   fi
-elif [ "$GOOS" == "freebsd" ]; then
+elif [ "$GOOS" = "freebsd" ]; then
   # The resulting object still depends on libc.
   # We removed this dependency for Go runtime for other OSes,
   # and we should remove it for FreeBSD as well, but there is no pressing need.
   DEPENDS_ON_LIBC=1
   OSCFLAGS="-fno-strict-aliasing -fPIC -Werror"
   ARCHCFLAGS="-m64"
   OSLDFLAGS="-lpthread -fPIC -fpie"
   SRCS="
     $SRCS
     ../rtl/tsan_platform_linux.cpp
     ../../sanitizer_common/sanitizer_posix.cpp
     ../../sanitizer_common/sanitizer_posix_libcdep.cpp
     ../../sanitizer_common/sanitizer_procmaps_bsd.cpp
     ../../sanitizer_common/sanitizer_procmaps_common.cpp
     ../../sanitizer_common/sanitizer_linux.cpp
     ../../sanitizer_common/sanitizer_linux_libcdep.cpp
     ../../sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cpp
     ../../sanitizer_common/sanitizer_stoptheworld_netbsd_libcdep.cpp
   "
-elif [ "$GOOS" == "netbsd" ]; then
+elif [ "$GOOS" = "netbsd" ]; then
   # The resulting object still depends on libc.
   # We removed this dependency for Go runtime for other OSes,
   # and we should remove it for NetBSD as well, but there is no pressing need.
   DEPENDS_ON_LIBC=1
   OSCFLAGS="-fno-strict-aliasing -fPIC -Werror"
   ARCHCFLAGS="-m64"
   OSLDFLAGS="-lpthread -fPIC -fpie"
   SRCS="
     $SRCS
     ../rtl/tsan_platform_linux.cpp
     ../../sanitizer_common/sanitizer_posix.cpp
     ../../sanitizer_common/sanitizer_posix_libcdep.cpp
     ../../sanitizer_common/sanitizer_procmaps_bsd.cpp
     ../../sanitizer_common/sanitizer_procmaps_common.cpp
     ../../sanitizer_common/sanitizer_linux.cpp
     ../../sanitizer_common/sanitizer_linux_libcdep.cpp
     ../../sanitizer_common/sanitizer_netbsd.cpp
     ../../sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cpp
     ../../sanitizer_common/sanitizer_stoptheworld_netbsd_libcdep.cpp
   "
-elif [ "$GOOS" == "darwin" ]; then
+elif [ "$GOOS" = "darwin" ]; then
   OSCFLAGS="-fPIC -Wno-unused-const-variable -Wno-unknown-warning-option -mmacosx-version-min=10.7"
   OSLDFLAGS="-lpthread -fPIC -fpie -mmacosx-version-min=10.7"
   SRCS="
     $SRCS
     ../rtl/tsan_platform_mac.cpp
     ../../sanitizer_common/sanitizer_mac.cpp
     ../../sanitizer_common/sanitizer_mac_libcdep.cpp
     ../../sanitizer_common/sanitizer_posix.cpp
     ../../sanitizer_common/sanitizer_posix_libcdep.cpp
     ../../sanitizer_common/sanitizer_procmaps_mac.cpp
   "
-  if [ "$GOARCH" == "amd64" ]; then
+  if [ "$GOARCH" = "amd64" ]; then
     ARCHCFLAGS="-m64"
-  elif [ "$GOARCH" == "arm64" ]; then
+  elif [ "$GOARCH" = "arm64" ]; then
     ARCHCFLAGS=""
   fi
-elif [ "$GOOS" == "windows" ]; then
+elif [ "$GOOS" = "windows" ]; then
   OSCFLAGS="-Wno-error=attributes -Wno-attributes -Wno-unused-const-variable -Wno-unknown-warning-option"
   ARCHCFLAGS="-m64"
   OSLDFLAGS=""
   SRCS="
     $SRCS
     ../rtl/tsan_platform_windows.cpp
     ../../sanitizer_common/sanitizer_win.cpp
   "

 # Verify that no libc specific code is present.
 if [ "$DEPENDS_ON_LIBC" != "1" ]; then
   if nm $DIR/race_$SUFFIX.syso | grep -q __libc_; then
     printf -- '%s seems to link to libc\n' "race_$SUFFIX.syso"
     exit 1
   fi
 fi
 
-if [ "$SKIP_TEST" == "1" ]; then
+if [ "$SKIP_TEST" = "1" ]; then
   exit 0
 fi
 
 if [ "`uname -a | grep NetBSD`" != "" ]; then
   # Turn off ASLR in the test binary.
   /usr/sbin/paxctl +a $DIR/test
 fi
 export GORACE="exitcode=0 atexit_sleep_ms=0"
 if [ "$SILENT" != "1" ]; then
   $DIR/test
 else
   $DIR/test 2>/dev/null
 fi