[clang] [llvm] [libc] remove references to LIBC_HDRGEN_ONLY (PR #118670)

[Nick Desaulniers via cfe-commits]

https://github.com/nickdesaulniers created https://github.com/llvm/llvm-project/pull/118670

Further cleanups from old hdrgen removal. I didn't realize there were cmake
variables related to old hdrgen spread out throughout more of the source tree.

Link: #117220
Link: #117208


>From ebb64d56b04182104f90783b86cf30e74ab00c3c Mon Sep 17 00:00:00 2001
From: Nick Desaulniers <ndesaulniers at google.com>
Date: Wed, 4 Dec 2024 09:20:01 -0800
Subject: [PATCH] [libc] remove references to LIBC_HDRGEN_ONLY

Further cleanups from old hdrgen removal. I didn't realize there were cmake
variables related to old hdrgen spread out throughout more of the source tree.

Link: #117220
Link: #117208
---
 clang/cmake/caches/Fuchsia-stage2.cmake | 1 -
 clang/cmake/caches/Fuchsia.cmake        | 1 -
 llvm/cmake/modules/CrossCompile.cmake   | 4 ++--
 3 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/clang/cmake/caches/Fuchsia-stage2.cmake b/clang/cmake/caches/Fuchsia-stage2.cmake
index 304e7833699a78..f6463d92cdd035 100644
--- a/clang/cmake/caches/Fuchsia-stage2.cmake
+++ b/clang/cmake/caches/Fuchsia-stage2.cmake
@@ -26,7 +26,6 @@ set(LLVM_FORCE_BUILD_RUNTIME ON CACHE BOOL "")
 set(LLVM_INCLUDE_DOCS OFF CACHE BOOL "")
 set(LLVM_INCLUDE_EXAMPLES OFF CACHE BOOL "")
 set(LLVM_LIBC_FULL_BUILD ON CACHE BOOL "")
-set(LIBC_HDRGEN_ONLY ON CACHE BOOL "")
 set(LLVM_STATIC_LINK_CXX_STDLIB ON CACHE BOOL "")
 set(LLVM_USE_RELATIVE_PATHS_IN_FILES ON CACHE BOOL "")
 set(LLDB_ENABLE_CURSES OFF CACHE BOOL "")
diff --git a/clang/cmake/caches/Fuchsia.cmake b/clang/cmake/caches/Fuchsia.cmake
index 2d2dcb9ae6798d..3118b5369298f4 100644
--- a/clang/cmake/caches/Fuchsia.cmake
+++ b/clang/cmake/caches/Fuchsia.cmake
@@ -17,7 +17,6 @@ set(LLVM_ENABLE_Z3_SOLVER OFF CACHE BOOL "")
 set(LLVM_ENABLE_ZLIB OFF CACHE BOOL "")
 set(LLVM_INCLUDE_DOCS OFF CACHE BOOL "")
 set(LLVM_INCLUDE_EXAMPLES OFF CACHE BOOL "")
-set(LIBC_HDRGEN_ONLY ON CACHE BOOL "")
 set(LLVM_USE_RELATIVE_PATHS_IN_FILES ON CACHE BOOL "")
 set(LLDB_ENABLE_CURSES OFF CACHE BOOL "")
 set(LLDB_ENABLE_LIBEDIT OFF CACHE BOOL "")
diff --git a/llvm/cmake/modules/CrossCompile.cmake b/llvm/cmake/modules/CrossCompile.cmake
index c22d185349dcc5..b0d36d8dbf4eb0 100644
--- a/llvm/cmake/modules/CrossCompile.cmake
+++ b/llvm/cmake/modules/CrossCompile.cmake
@@ -69,8 +69,8 @@ function(llvm_create_cross_target project_name target_name toolchain buildtype)
          "-DLLVM_EXTERNAL_${name}_SOURCE_DIR=${LLVM_EXTERNAL_${name}_SOURCE_DIR}")
   endforeach()
 
-  if("libc" IN_LIST LLVM_ENABLE_PROJECTS AND NOT LIBC_HDRGEN_EXE)
-    set(libc_flags -DLLVM_LIBC_FULL_BUILD=ON -DLIBC_HDRGEN_ONLY=ON)
+  if("libc" IN_LIST LLVM_ENABLE_PROJECTS)
+    set(libc_flags -DLLVM_LIBC_FULL_BUILD=ON)
     if(MSVC)
       # Due to some issues mentioned in llvm/projects/CMakeLists.txt, libc build is disabled by
       # default in the cross target when building with MSVC compatible compilers on Windows. Add