[LLDB] Add API to SBTarget not to flush for SetSectionLoadAddress

Summary:
A custom JIT can be invoked in the middle of unwinding to load
debug information. In this case we do not want to flush the process.

Test Plan: ninja check-lldb

Rollback Plan:

Reviewers: gclayton, joh, #lldb_team

Reviewed By: gclayton

Differential Revision: https://phabricator.intern.facebook.com/D77634921

Tasks: T227178858

Author: Alexander Yermolovich

lldb/include/lldb/API/SBTarget.h

@@ -395,6 +395,25 @@ class LLDB_API SBTarget {
   lldb::SBError SetSectionLoadAddress(lldb::SBSection section,
                                       lldb::addr_t section_base_addr);
 
+  /// Set the base load address for a module section.
+  ///
+  /// \param[in] section
+  ///     The section whose base load address will be set within this
+  ///     target.
+  ///
+  /// \param[in] section_base_addr
+  ///     The base address for the section.
+  ///
+  /// \param[in] should_flush
+  ///     Controls whether process should be flushed after adddress is set.
+  ///
+  /// \return
+  ///      An error to indicate success, fail, and any reason for
+  ///     failure.
+  lldb::SBError SetSectionLoadAddress(lldb::SBSection section,
+                                      lldb::addr_t section_base_addr,
+                                      bool should_flush);
+
   /// Clear the base load address for a module section.
   ///
   /// \param[in] section

lldb/source/API/SBTarget.cpp

@@ -2071,6 +2071,12 @@ SBTarget::GetInstructionsWithFlavor(lldb::addr_t base_addr,
 
 SBError SBTarget::SetSectionLoadAddress(lldb::SBSection section,
                                         lldb::addr_t section_base_addr) {
+  return SetSectionLoadAddress(section, section_base_addr, true);
+}
+
+SBError SBTarget::SetSectionLoadAddress(lldb::SBSection section,
+                                        lldb::addr_t section_base_addr,
+                                        bool should_flush) {
   LLDB_INSTRUMENT_VA(this, section, section_base_addr);
 
   SBError sb_error;
@@ -2093,7 +2099,7 @@ SBError SBTarget::SetSectionLoadAddress(lldb::SBSection section,
               target_sp->ModulesDidLoad(module_list);
             }
             // Flush info in the process (stack frames, etc)
-            if (process_sp)
+            if (process_sp && should_flush)
               process_sp->Flush();
           }
         }