[heap] Remove max executable size configuration.

src/s390/assembler-s390.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions
 // are met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 1348 matching lines @@
   // label reference or kEndOfChain.
   int target_at(int pos);
 
   // Patch instruction(s) at pos to target target_pos (e.g. branch)
   void target_at_put(int pos, int target_pos, bool* is_branch = nullptr);
 
   // Record reloc info for current pc_
   void RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data = 0);
 
  private:
+  // Avoid overflows for displacements etc.
+  static const int kMaximalBufferSize = 512 * MB;
+
   // Code generation
   // The relocation writer's position is at least kGap bytes below the end of
   // the generated instructions. This is so that multi-instruction sequences do
   // not have to check for overflow. The same is true for writes of large
   // relocation info entries.
   static constexpr int kGap = 32;
 
   // Relocation info generation
   // Each relocation is encoded as a variable size value
   static constexpr int kMaxRelocSize = RelocInfoWriter::kMaxSize;
@@ skipping 96 matching lines @@
 
 class EnsureSpace BASE_EMBEDDED {
  public:
   explicit EnsureSpace(Assembler* assembler) { assembler->CheckBuffer(); }
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_S390_ASSEMBLER_S390_H_