Revert (2) "[AST] Add RParen loc for decltype AutoTypeloc."

This reverts commit 41fbdfa4.

The commit breaks stage 2 builds with debug info, e.g.
https://green.lab.llvm.org/green/job/clang-stage2-Rthinlto/5088/console

Clang crashes with the following assertion when building
llvm-project/llvm/lib/Support/Timer.cpp

/usr/local/bin/sccache /Users/buildslave/jenkins/workspace/clang-stage2-Rthinlto/host-compiler/bin/clang++  -DGTEST_HAS_RTTI=0 -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -Ilib/Support -I/Users/buildslave/jenkins/workspace/clang-stage2-Rthinlto/llvm-project/llvm/lib/Support -Iinclude -I/Users/buildslave/jenkins/workspace/clang-stage2-Rthinlto/llvm-project/llvm/include -fno-stack-protector -fno-common -Wno-profile-instr-unprofiled -fPIC -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -fmodules -fmodules-cache-path=/Users/buildslave/jenkins/workspace/clang-stage2-Rthinlto/clang-build/Build/module.cache -fcxx-modules -Xclang -fmodules-local-submodule-visibility -gmodules -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -fdiagnostics-color -flto=thin  -O2 -g -DNDEBUG -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk   -std=c++14  -fno-exceptions -fno-rtti -MD -MT lib/Support/CMakeFiles/LLVMSupport.dir/Timer.cpp.o -MF lib/Support/CMakeFiles/LLVMSupport.dir/Timer.cpp.o.d -o lib/Support/CMakeFiles/LLVMSupport.dir/Timer.cpp.o -c /Users/buildslave/jenkins/workspace/clang-stage2-Rthinlto/llvm-project/llvm/lib/Support/Timer.cpp
Assertion failed: (((getOffset()+Offset) & MacroIDBit) == 0 && "offset overflow"), function getLocWithOffset, file /Users/buildslave/jenkins/workspace/clang-stage1-RA/llvm-project/clang/include/clang/Basic/SourceLocation.h, line 135.