x86: remove alternative_callN usage of ALTERNATIVE asm macro

x86: remove alternative_callN usage of ALTERNATIVE asm macro

There is a bug in llvm that needs to be fixed before switching to use
the alternative assembly macros in inline assembly call sites.
Therefore alternative_callN using inline assembly to generate the
alternative patch sites should be using the ALTERNATIVE C preprocessor
macro rather than the ALTERNATIVE assembly macro. Using the assembly
macro in an inline assembly instance triggers the following bug on
llvm based toolchains:

<instantiation>:1:1: error: invalid symbol redefinition
.L0_orig_s: call *genapic+64(%rip); .L0_orig_e: .L0_diff = (.L0_repl_e1 - .L0_repl_s1) - (...
^
<instantiation>:1:37: error: invalid symbol redefinition
.L0_orig_s: call *genapic+64(%rip); .L0_orig_e: .L0_diff = (.L0_repl_e1 - .L0_repl_s1) - (...
                                    ^
<instantiation>:1:60: error: invalid reassignment of non-absolute variable '.L0_diff'
.L0_orig_s: call *genapic+64(%rip); .L0_orig_e: .L0_diff = (.L0_repl_e1 - .L0_repl_s1) - (...
                                                           ^
<inline asm>:1:2: note: while in macro instantiation
        ALTERNATIVE "call *genapic+64(%rip)", "call .", X86_FEATURE_LM
        ^
<instantiation>:1:156: error: invalid symbol redefinition
  ...- (.L0_orig_e - .L0_orig_s); mknops ((-(.L0_diff > 0)) * .L0_diff); .L0_orig_p:
                                                                         ^
<instantiation>:18:5: error: invalid symbol redefinition
    .L0_repl_s1: call .; .L0_repl_e1:
    ^
<instantiation>:18:26: error: invalid symbol redefinition
    .L0_repl_s1: call .; .L0_repl_e1:
                         ^
<instantiation>:1:1: error: invalid symbol redefinition
.L0_orig_s: call *genapic+64(%rip); .L0_orig_e: .L0_diff = (.L0_repl_e1 - .L0_repl_s1) - (...
^
<instantiation>:1:37: error: invalid symbol redefinition
.L0_orig_s: call *genapic+64(%rip); .L0_orig_e: .L0_diff = (.L0_repl_e1 - .L0_repl_s1) - (...
                                    ^
<instantiation>:1:60: error: invalid reassignment of non-absolute variable '.L0_diff'
.L0_orig_s: call *genapic+64(%rip); .L0_orig_e: .L0_diff = (.L0_repl_e1 - .L0_repl_s1) - (...
                                                           ^
<inline asm>:1:2: note: while in macro instantiation
        ALTERNATIVE "call *genapic+64(%rip)", "call .", X86_FEATURE_LM
        ^
<instantiation>:1:156: error: invalid symbol redefinition
  ...- (.L0_orig_e - .L0_orig_s); mknops ((-(.L0_diff > 0)) * .L0_diff); .L0_orig_p:
                                                                         ^
<instantiation>:18:5: error: invalid symbol redefinition
    .L0_repl_s1: call .; .L0_repl_e1:
    ^
<instantiation>:18:26: error: invalid symbol redefinition
    .L0_repl_s1: call .; .L0_repl_e1:
                         ^
<instantiation>:1:1: error: invalid symbol redefinition
.L0_orig_s: call *genapic+64(%rip); .L0_orig_e: .L0_diff = (.L0_repl_e1 - .L0_repl_s1) - (...
^
<instantiation>:1:37: error: invalid symbol redefinition
.L0_orig_s: call *genapic+64(%rip); .L0_orig_e: .L0_diff = (.L0_repl_e1 - .L0_repl_s1) - (...
                                    ^
<instantiation>:1:60: error: invalid reassignment of non-absolute variable '.L0_diff'
.L0_orig_s: call *genapic+64(%rip); .L0_orig_e: .L0_diff = (.L0_repl_e1 - .L0_repl_s1) - (...
                                                           ^
<inline asm>:1:2: note: while in macro instantiation
        ALTERNATIVE "call *genapic+64(%rip)", "call .", X86_FEATURE_LM
        ^
<instantiation>:1:156: error: invalid symbol redefinition
  ...- (.L0_orig_e - .L0_orig_s); mknops ((-(.L0_diff > 0)) * .L0_diff); .L0_orig_p:
                                                                         ^
<instantiation>:18:5: error: invalid symbol redefinition
    .L0_repl_s1: call .; .L0_repl_e1:
    ^
<instantiation>:18:26: error: invalid symbol redefinition
    .L0_repl_s1: call .; .L0_repl_e1:
                         ^

This has been reported to upstream llvm:

https://bugs.llvm.org/show_bug.cgi?id=42034

Fixes: 67d01cdb5 ("x86: infrastructure to allow converting certain indirect calls to direct ones")
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>