[libc] revert all process_mrelease changes (llvm#118650)

Revert as its test is unstable.
llvm#118057

Author: SchrodingerZhu

libc/config/linux/aarch64/entrypoints.txt

@@ -252,7 +252,6 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.sys.mman.munlockall
     libc.src.sys.mman.munmap
     libc.src.sys.mman.remap_file_pages
-    libc.src.sys.mman.process_mrelease
     libc.src.sys.mman.posix_madvise
     libc.src.sys.mman.shm_open
     libc.src.sys.mman.shm_unlink

libc/config/linux/riscv/entrypoints.txt

@@ -251,8 +251,6 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.sys.mman.munmap
     libc.src.sys.mman.remap_file_pages
     libc.src.sys.mman.posix_madvise
-    # TODO: disabled due to buildbot failure. further investigation needed.
-    # libc.src.sys.mman.process_mrelease
     libc.src.sys.mman.shm_open
     libc.src.sys.mman.shm_unlink
 

libc/config/linux/x86_64/entrypoints.txt

@@ -252,7 +252,6 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.sys.mman.munmap
     libc.src.sys.mman.remap_file_pages
     libc.src.sys.mman.posix_madvise
-    libc.src.sys.mman.process_mrelease
     libc.src.sys.mman.shm_open
     libc.src.sys.mman.shm_unlink
 

libc/hdrgen/yaml/sys/mman.yaml

@@ -132,10 +132,3 @@ functions:
     return_type: int
     arguments:
       - type: const char *
-  - name: process_mrelease
-    standards:
-      - Linux
-    return_type: int
-    arguments:
-      - type: int
-      - type: unsigned int

libc/include/sys/syscall.h.def

@@ -2349,12 +2349,5 @@
 #define SYS_writev __NR_writev
 #endif
 
-#ifdef __NR_process_mrelease
-#define SYS_process_mrelease __NR_process_mrelease
-#endif
-
-#ifdef __NR_pidfd_open
-#define SYS_pidfd_open __NR_pidfd_open
-#endif
 
 #endif // LLVM_LIBC_SYS_SYSCALL_H

libc/src/sys/mman/CMakeLists.txt

@@ -113,9 +113,3 @@ add_entrypoint_object(
   DEPENDS
     .${LIBC_TARGET_OS}.mremap
 )
-
-add_entrypoint_object(
-  process_mrelease 
-  ALIAS 
-  DEPENDS
-    .${LIBC_TARGET_OS}.process_mrelease)

libc/src/sys/mman/linux/CMakeLists.txt

@@ -36,6 +36,7 @@ add_entrypoint_object(
     libc.src.__support.OSUtil.osutil
     libc.src.errno.errno
 )
+
 add_entrypoint_object(
   munmap
   SRCS
@@ -213,14 +214,3 @@ add_entrypoint_object(
     libc.src.unistd.unlink
     .shm_common
 )
-
-add_entrypoint_object(
-  process_mrelease
-  SRCS
-    process_mrelease.cpp
-  HDRS
-    ../process_mrelease.h
-  DEPENDS
-    libc.include.sys_syscall
-    libc.src.__support.OSUtil.osutil
-    libc.src.errno.errno)

libc/src/sys/mman/linux/process_mrelease.cpp

@@ -181,24 +181,3 @@ add_libc_unittest(
     libc.hdr.fcntl_macros
     libc.test.UnitTest.ErrnoSetterMatcher
 )
-
-add_libc_unittest(
-  process_mrelease_test
-  SUITE
-    libc_sys_mman_unittests
-  SRCS
-    process_mrelease_test.cpp
-  DEPENDS
-    libc.include.sys_mman
-    libc.include.sys_syscall
-    libc.src.errno.errno
-    libc.src.sys.mman.process_mrelease
-    libc.src.unistd.close
-    libc.src.signal.kill
-    libc.include.signal
-    libc.src.stdlib.exit
-    libc.src.signal.raise
-    libc.src.__support.OSUtil.osutil
-    libc.src.__support.threads.sleep
-    libc.test.UnitTest.ErrnoSetterMatcher
-)