Revert "Adding GDB PrettyPrinter for mlir::Identifier."

This reverts commit 9e9e6e698d8ef5dc5b7576058f2022aab2534a52.

This commit is causing builds that include the 'debuginfo-tests' project to
fail.

Apple has a public bot which shows the failure:
http://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/23667/console

GitOrigin-RevId: 485e6db8729383345da9796218d99843449057ac
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3750f2e..d3ac0a4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -9,12 +9,6 @@
 )
 target_link_libraries(check-gdb-llvm-support PRIVATE LLVMSupport)
 
-add_llvm_executable(check-gdb-mlir-support
-        llvm-prettyprinters/gdb/mlir-support.cpp
-)
-target_include_directories(check-gdb-mlir-support PRIVATE ${LLVM_EXTERNAL_MLIR_SOURCE_DIR}/include)
-target_link_libraries(check-gdb-mlir-support PRIVATE MLIRIR)
-
 set(DEBUGINFO_TESTS_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
 set(DEBUGINFO_TESTS_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR})
 
@@ -25,7 +19,6 @@
   llvm-config
   llvm-objdump
   check-gdb-llvm-support
-  check-gdb-mlir-support
   not
   )
 
diff --git a/lit.cfg.py b/lit.cfg.py
index ba09b1f..4c45b72 100644
--- a/lit.cfg.py
+++ b/lit.cfg.py
@@ -46,7 +46,6 @@
         config.debuginfo_tests_src_root, 'llgdb-tests', 'test_debuginfo.pl')),
     ToolSubst("%llvm_src_root", config.llvm_src_root),
     ToolSubst("%llvm_tools_dir", config.llvm_tools_dir),
-    ToolSubst("%mlir_src_root", config.mlir_src_root),
 ]
 
 def get_required_attr(config, attr_name):
diff --git a/lit.site.cfg.py.in b/lit.site.cfg.py.in
index 4ed49b8..d5893f5 100644
--- a/lit.site.cfg.py.in
+++ b/lit.site.cfg.py.in
@@ -20,8 +20,6 @@
 config.host_arch = "@HOST_ARCH@"
 config.is_msvc = lit.util.pythonize_bool("@MSVC@")
 
-config.mlir_src_root = "@MLIR_SOURCE_DIR@"
-
 config.llvm_use_sanitizer = "@LLVM_USE_SANITIZER@"
 
 config.python3_executable = "@Python3_EXECUTABLE@"
diff --git a/llvm-prettyprinters/gdb/mlir-support.cpp b/llvm-prettyprinters/gdb/mlir-support.cpp
deleted file mode 100644
index d38fc3d..0000000
--- a/llvm-prettyprinters/gdb/mlir-support.cpp
+++ /dev/null
@@ -1,8 +0,0 @@
-#include "mlir/IR/Identifier.h"
-#include "mlir/IR/MLIRContext.h"
-
-mlir::MLIRContext Context;
-
-auto Identifier = mlir::Identifier::get("foo", &Context);
-
-int main() { return 0; }
diff --git a/llvm-prettyprinters/gdb/mlir-support.gdb b/llvm-prettyprinters/gdb/mlir-support.gdb
deleted file mode 100644
index cca435e..0000000
--- a/llvm-prettyprinters/gdb/mlir-support.gdb
+++ /dev/null
@@ -1,8 +0,0 @@
-# RUN: gdb -q -batch -n -iex 'source %mlir_src_root/utils/gdb-scripts/prettyprinters.py' -x %s %llvm_tools_dir/check-gdb-mlir-support | FileCheck %s --dump-input=fail
-# REQUIRES: debug-info
-
-break main
-run
-
-# CHECK: "foo"
-p Identifier