Remove workaround for C++14

C++17 was fully enabled [1] a few days after the last try to remove the
workaround [2]. Let's try again now.

[1] https://crrev.com/c/3316556
[2] https://crrev.com/c/3306429

R=leszeks@chromium.org

Change-Id: I63696b69d8d47deead03b86822ad04fbe065d7d3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3785144Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81963}

include/v8config.h

@@ -623,13 +623,6 @@ V8 shared library set USING_V8_SHARED.
 
 #endif  // V8_OS_WIN
 
-// From C++17 onwards, static constexpr member variables are defined to be
-// "inline", and adding a separate definition for them can trigger deprecation
-// warnings. For C++14 and below, however, these definitions are required.
-#if __cplusplus < 201703L && (!defined(_MSVC_LANG) || _MSVC_LANG < 201703L)
-#define V8_STATIC_CONSTEXPR_VARIABLES_NEED_DEFINITIONS
-#endif
-
 // clang-format on
 
 // Processor architecture detection.  For more info on what's defined, see:

src/compiler/js-heap-broker.cc

@@ -25,14 +25,6 @@ namespace compiler {
 
 #define TRACE(broker, x) TRACE_BROKER(broker, x)
 
-#ifdef V8_STATIC_CONSTEXPR_VARIABLES_NEED_DEFINITIONS
-// These definitions are here in order to please the linker, which in debug mode
-// sometimes requires static constants to be defined in .cc files.
-// This is, however, deprecated (and unnecessary) in C++17.
-const uint32_t JSHeapBroker::kMinimalRefsBucketCount;
-const uint32_t JSHeapBroker::kInitialRefsBucketCount;
-#endif
-
 void JSHeapBroker::IncrementTracingIndentation() { ++trace_indentation_; }
 
 void JSHeapBroker::DecrementTracingIndentation() { --trace_indentation_; }