Correctly detect if linker supports noexecstack

When testing for support of multiple flags, the flags must be separated
by semicolons not spaces.

See https://gitlab.kitware.com/cmake/cmake/-/issues/26024

When referenced elsewhere, enclose the flag variable in quotation marks
so that it is passed through unmodified.

Closes facebook#4056

build/cmake/CMakeModules/AddZstdCompilationFlags.cmake

@@ -17,13 +17,13 @@ function(EnableCompilerFlag _flag _C _CXX _LD)
  string(REGEX REPLACE "^_+" "" varname "${varname}")
  string(TOUPPER "${varname}" varname)
  if (_C)
- CHECK_C_COMPILER_FLAG(${_flag} C_FLAG_${varname})
+ CHECK_C_COMPILER_FLAG("${_flag}" C_FLAG_${varname})
  if (C_FLAG_${varname})
  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${_flag}" PARENT_SCOPE)
  endif ()
  endif ()
  if (_CXX)
- CHECK_CXX_COMPILER_FLAG(${_flag} CXX_FLAG_${varname})
+ CHECK_CXX_COMPILER_FLAG("${_flag}" CXX_FLAG_${varname})
  if (CXX_FLAG_${varname})
  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${_flag}" PARENT_SCOPE)
  endif ()
@@ -39,7 +39,7 @@ function(EnableCompilerFlag _flag _C _CXX _LD)
  # results for this configuration,
  # see: https://gitlab.kitware.com/cmake/cmake/-/issues/22023
  if (ZSTD_HAVE_CHECK_LINKER_FLAG AND NOT MSVC)
- CHECK_LINKER_FLAG(C ${_flag} LD_FLAG_${varname})
+ CHECK_LINKER_FLAG(C "${_flag}" LD_FLAG_${varname})
  else ()
  set(LD_FLAG_${varname} false)
  endif ()
@@ -76,7 +76,7 @@ macro(ADD_ZSTD_COMPILATION_FLAGS)
  endif ()
  # Add noexecstack flags
  # LDFLAGS
- EnableCompilerFlag("-z noexecstack" false false true)
+ EnableCompilerFlag("-z;noexecstack" false false true)
  # CFLAGS & CXXFLAGS
  EnableCompilerFlag("-Qunused-arguments" true true false)
  EnableCompilerFlag("-Wa,--noexecstack" true true false)