[heap] Remove max executable size configuration.

src/s390/assembler-s390.h

Index: src/s390/assembler-s390.h
diff --git a/src/s390/assembler-s390.h b/src/s390/assembler-s390.h
index 311ecfcab0bacb375a75b951b9541960a36b091a..bee7452aaa9a4e2b65435d83f8d2db6626adbf9a 100644
--- a/src/s390/assembler-s390.h
+++ b/src/s390/assembler-s390.h
@@ -1366,6 +1366,9 @@ class Assembler : public AssemblerBase {
   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