[NativeAOT-LLVM] Remove various file reading (Linux specific) paths

[SingleAccretion]

Fixes #2947. Includes a wasmjit-diff.ps1 change that makes it work with components.

Diffs (WasmDebugging):

Summary of Code Size diffs:
(Lower is better)

Total bytes of base: 772104
Total bytes of diff: 752689
Total bytes of delta: -19415 (-2.51% % of base)
Average relative delta: -5.53%
    diff is an improvement
    average relative diff is an improvement

Top method regressions (percentages):
          15 ( 5.70% of base) : 1002.dasm - GCToOSInterface::GetMemoryStatus(unsigned long long, unsigned int*, unsigned long long*, unsigned long long*)

Top method improvements (percentages):
        -658 (-99.70% of base) : 1003.dasm - InitializeCGroup()
        -263 (-98.50% of base) : 1004.dasm - GetPhysicalMemoryUsed(unsigned long*)
         -17 (-89.47% of base) : 1005.dasm - InitializeCpuCGroup()

Top methods only present in base:
          -3 (-100.00% of base) : 1000.dasm - undefined_weak:__wasilibc_find_relpath_alloc
         -52 (-100.00% of base) : 1027.dasm - __ofl_add
         -55 (-100.00% of base) : 1028.dasm - sscanf
         -36 (-100.00% of base) : 1029.dasm - fputs
        -174 (-100.00% of base) : 1030.dasm - scalbn
        -538 (-100.00% of base) : 1031.dasm - fmod
       -4811 (-100.00% of base) : 1032.dasm - __floatscan
       -1403 (-100.00% of base) : 1033.dasm - hexfloat
        -595 (-100.00% of base) : 1034.dasm - scanexp
        -402 (-100.00% of base) : 1035.dasm - mbrtowc
         -18 (-100.00% of base) : 1036.dasm - mbsinit
         -16 (-100.00% of base) : 1026.dasm - getline
       -3081 (-100.00% of base) : 1037.dasm - vfscanf
         -88 (-100.00% of base) : 1039.dasm - vsscanf
         -93 (-100.00% of base) : 1040.dasm - string_read
        -370 (-100.00% of base) : 1041.dasm - memchr
         -73 (-100.00% of base) : 1042.dasm - memcmp
         -24 (-100.00% of base) : 1043.dasm - strcat
         -29 (-100.00% of base) : 1044.dasm - strchr
        -360 (-100.00% of base) : 1045.dasm - strstr
        -178 (-100.00% of base) : 1046.dasm - fourbyte_strstr
       -1002 (-100.00% of base) : 1047.dasm - twoway_strstr
        -247 (-100.00% of base) : 1048.dasm - strspn
         -28 (-100.00% of base) : 1038.dasm - long_double_not_supported
        -240 (-100.00% of base) : 1049.dasm - strcspn
        -585 (-100.00% of base) : 1025.dasm - getdelim
        -389 (-100.00% of base) : 1023.dasm - __fdopen
        -404 (-100.00% of base) : 1001.dasm - GetAvailablePhysicalMemory()
        -267 (-100.00% of base) : 1006.dasm - CGroup::FindCGroupPath(bool (*)(char const*))
        -557 (-100.00% of base) : 1007.dasm - CGroup::FindHierarchyMount(bool (*)(char const*), char**, char**)
        -209 (-100.00% of base) : 1008.dasm - CGroup::FindCGroupPathForSubsystem(bool (*)(char const*))
        -112 (-100.00% of base) : 1009.dasm - read
         -17 (-100.00% of base) : 1010.dasm - __wasi_fd_fdstat_set_flags
        -101 (-100.00% of base) : 1024.dasm - fopen
         -37 (-100.00% of base) : 1012.dasm - __wasi_path_open
        -281 (-100.00% of base) : 1013.dasm - __wasilibc_nocwd_openat_nomode
         -21 (-100.00% of base) : 1011.dasm - __wasi_fd_read
         -93 (-100.00% of base) : 1015.dasm - __wasilibc_find_relpath
        -342 (-100.00% of base) : 1016.dasm - __wasilibc_find_abspath
          -2 (-100.00% of base) : 1017.dasm - dummy
        -151 (-100.00% of base) : 1018.dasm - fclose
        -101 (-100.00% of base) : 1019.dasm - __fmodeflags
        -274 (-100.00% of base) : 1020.dasm - fcntl
        -113 (-100.00% of base) : 1021.dasm - readv
        -252 (-100.00% of base) : 1022.dasm - __stdio_read
        -161 (-100.00% of base) : 1014.dasm - __wasilibc_open_nomode
        -107 (-100.00% of base) : 1050.dasm - strtok_r

51 total methods with Code Size differences (50 improved, 1 regressed)

[SingleAccretion]

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