utils: Add FastStrcmp.h

Move existing fast<str*cmp> templates for general use, pulled from
the implementation used in logd that dealt with speed through cache
locality and subroutine call mitigation.  Rename to fastcmp.

Test: logd-benchmarks and based on manual profiling from the past
Bug: 31456426
Change-Id: Ic62f4a437fc3e06ffdeaae73a6f34e197957a6b0
diff --git a/logd/LogStatistics.cpp b/logd/LogStatistics.cpp
index d4b48ef..bab87ba 100644
--- a/logd/LogStatistics.cpp
+++ b/logd/LogStatistics.cpp
@@ -53,7 +53,7 @@
             if (ret > 0) {
                 buffer[sizeof(buffer)-1] = '\0';
                 // frameworks intermediate state
-                if (fast<strcmp>(buffer, "<pre-initialized>")) {
+                if (fastcmp<strcmp>(buffer, "<pre-initialized>")) {
                     retval = strdup(buffer);
                 }
             }
@@ -209,7 +209,7 @@
             if (nameTmp) {
                 if (!name) {
                     name = strdup(nameTmp);
-                } else if (fast<strcmp>(name, nameTmp)) {
+                } else if (fastcmp<strcmp>(name, nameTmp)) {
                     free(const_cast<char *>(name));
                     name = NULL;
                     break;